COVID-19 vaccines in people with immunocompromise

Background

COVID-19 vaccination is recommended for all people who are immunocompromised due to the increased risk of developing severe disease if exposed to SARS-CoV-2All COVID-19 vaccines in Australia are inactivated (non-live) vaccinesThe following guidance encompasses a broad group of conditions and therapies, as well as providing specific recommendations and/or links where available. People who are immunocompromised include those who are immunocompromised due to pre-existing illness (eg. cancer, immune deficiencies) as well as those who are taking immunomodulatory or immunosuppressive therapies. 

Due to the restricted eligibility criteria in early vaccine clinical trials, there is currently minimal data on the safety and efficacy of COVID-19 vaccination in this group. In principle, there are no theoretical safety risks and no vaccine safety signals have been identified for people with immunocompromise to date. Information on safetyefficacy and specific timing of immunosuppression and vaccination is expected in the coming months. People with immunocompromise receiving COVID-19 vaccination should be counselled about the possibility of reduced efficacy and the need to continue other preventative measures such as social distancingmask wearing and hand hygiene. Household contacts should be encouraged to receive the  COVID-19 vaccine when it is offered because vaccination has also been shown to reduce transmission. 

ATAGI has provided both a COVID-19 vaccination decision guide for people with immunocompromiseand a provider guide to COVID-19 vaccination of people with immunocompromise. 

Is there a specific vaccine preference for people who are immunocompromised?

Both Comirnaty™ and COVID-19 AstraZeneca can be used in people with immunocompromise in accordance with the ATAGI recommendations based on age. 

Some immunocompromising conditions such as cancer carry an increased risk of clotting and may result in deep vein thrombosis (DVT) and pulmonary embolism (PE). Having a past history of these conditions has not been linked to the development of thrombosis with thrombocytopenia syndrome (TTS) following administration of COVID-19 AstraZeneca vaccineCurrently, ATAGI recommends that anyone with a history of only central venous sinus thrombosis (CVST) or heparin-induced thrombocytopenia (HIT) should defer vaccination with any COVID-19 vaccine as a precautionary measure. 

Are there any safety concerns with the use of COVID-19 vaccines in people who are immunocompromised?

Much like other non-live vaccines, there are no specific safety concerns regarding the administration of COVID-19 vaccines in patients who are immunocompromised. Similarly, there have been no safety signals indicating disease flares in people with inflammatory/autoimmune conditions observed in the global rollout of COVID-19 vaccines thus far.  

To avoid confusion between side effects of vaccination and certain immunomodulatory therapies, where possible treating clinicians should consider administering vaccination on a different day from treatment/therapy. The Australasian Society of Clinical Immunology and Allergy (ASCIA) has provided guidance about COVID-19 vaccination and the timing of immunomodulatory therapies. Specifically, the Australian and New Zealand Association of Neurologists (ANZAN) in collaboration with MS Research Australia, have recommended that people with multiple sclerosis be vaccinated against COVID-19 and provided general advice about immunosuppressive and immunomodulatory therapy, as well as vaccine safety. 

People on immune checkpoint inhibitors (ICI) are recommended to be vaccinated against COVID-19. small study of 134 patient on ICI showed no difference in short-term safety or undesired/harmful effects (reactogenicity) compared with the control group. However, people on dual ICI therapy should discuss optimal timing of vaccination with their treating clinician prior to vaccination.  

What is the efficacy of COVID-19 vaccines in people who are immunocompromised? 

People who are immunocompromised may have a reduced response to vaccination. Similar to other inactivated vaccines, some immunocompromising conditions and immunosuppressive medications are also expected to reduce the immune response to COVID-19 vaccines. Currently, there is no established immune correlate of protection against COVID-19 to provide guidance about either the requirement for booster doses or reducing the need for other preventative measures. 

There are currently limited peer-reviewed studies in people who have received COVID-19 vaccines and who are on concurrent immunosuppressive treatment for rheumatological and musculoskeletal conditionsinflammatory bowel disease or following a solid-organ transplant 

Are there recommendations for the timing of immunosuppressive medications and the administration of COVID-19 vaccines in people who are taking immunomodulatory or immunosuppressive therapies? 

There is no information specific to COVID-19 vaccination to support recommendations about modifying immunosuppressive medication timing or doses to increase vaccine efficacy. Vaccination to protect against COVID-19 should therefore follow the general principles of vaccination and immunosuppressionAdministration of COVID-19 vaccine should be planned with the treating specialist and in some instances, the timing of immune suppressive therapies may be altered to increase the response to vaccination.  

Delaying initiation or interrupting cancer therapy to potentially improve the response to vaccination is not recommended. When considering vaccination during cancer treatment, it is preferable to defer vaccination if severe neutropenia is present (< 0.5 x 109/L) and where possible, to time vaccination between treatment cycles.  

Two doses of COVID-19 vaccination should preferably be completed at least two weeks prior to the commencement of immunosuppressive therapy, transplant or planned splenectomy. For people who are about to start immunosuppressive therapy or are between courses of treatment, the interval between COVID-19 vaccine doses can be reduced from 21days to 19 days for Comirnaty  and from 12 weeks to 28 days for COVID-19 AstraZeneca. If it is not feasible to complete the 2nd dose prior to immunosuppression, then the 2nd dose should still be given as per the recommended schedule.    

There is no direct evidence for the temporary cessation of immunosuppressive therapy before or after COVID-19 vaccination. For the inactivated influenza vaccination in patients with rheumatoid arthritis, temporary methotrexate discontinuation improves the antibody response to influenza vaccines but it is not known whether this improves clinical protection. People with rheumatological and inflammatory conditions with low disease activity or people nearing planned completion of immunosuppressive therapy should discuss the timing of their vaccination with their treating clinician. Persons who have received a solid organ or stem cell transplant should discuss timing of COVID-19 vaccination with their treating clinician. Further information for people with autoinflammatory and rheumatological diseases on immunomodulatory therapies can be found on the Australian Rheumatology Association FAQ and evidence review on COVID-19 vaccination or guidance from ASCIAGESA and MS Australia. 

There are some specific therapies that are highly likely to reduce vaccine responses based on what is known about their responses to other inactivated vaccines. People who take B cell depleting therapies (eg. rituximab or ocrelizumab) or medications that block T-cell dependent B memory cells (eg. abatacept) should discuss timing of their vaccines with their treating clinicians. We recommended that patients on rituximab be vaccinated against COVID-19. For patients on 6 monthly rituximab, where possible should receive the first dose of their COVID-19 vaccine schedule 4 weeks prior to the next scheduled infusion and delay the next infusion by 2-4 weeks after the 2nd vaccine dose (noting the different interval requirements for each COVID-19 vaccine brand). This may not always be possible due to activity of the underlying condition and should be decided on a case-by-case basis. Whilst COVID-19 incidence remains low in Australia, it may be reasonable to defer vaccination for patients who are scheduled to cease B-cell depleting therapy and vaccinate once there is immune reconstitution. 

Should people who are immunosuppressed have a booster dose or have SARS-CoV-2 antibodies measured after vaccination?  

Antibody testing or additional booster doses are not recommended at this time as there is no established immune correlate of protection against COVID-19 disease.

Resources

Authors: Jeremy Carr (Paediatric Infectious Diseases Consultant, Monash Health), Shidan Tosif (Paediatrician, Royal Children's Hospital), Andres Noe (DPhil candidate, The Jenner Institute), Nigel Crawford (SAEFVIC Director, Murdoch Children's Research Institute), Daryl Cheng (Medical Lead, MVEC), Francesca Machingaifa (Education Nurse Coordinator, MVEC) and Rachael McGuire (Education Nurse Coordinator, MVEC)

Date: May 2021

Materials in this section are updated as new information and vaccines become available. The Melbourne Vaccine Education Centre (MVEC) staff regularly reviews materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family’s personal health. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult a healthcare professional.


COVID-19 vaccine adverse events

Background

  • Anyone who experiences a significant reaction following immunisation should first seek medical attention from a health professional
  • While no vaccine is entirely free of potential side effects, the benefits of immunisation far outweigh the risks
  • Severe side effects from vaccines are rare and common side effects are usually mild and short lasting

Should all AEFIs (adverse events following immunisation) following COVID-19 vaccines be reported?

You do not need to routinely report:

  • Common/expected reactions
  • These may include pain, redness, swelling and tenderness at the injection site, tiredness, headache, muscle pain, nausea, fever and chills, feeling unwell, joint pain

You should report:

  • Any event felt to be significant following COVID-19 immunisation, regardless of whether you think the side effect was related to the vaccine or not
  • Any expected reactions that have not gone away after a few days
  • Any reaction to a vaccine which requires assessment by a doctor or nurse
  • Suspected shoulder injury related to vaccine administration (SIRVA)
  • Any vaccination administration errors

COVID-19 AstraZeneca side effects

Common side effects following vaccination with COVID-19 AstraZeneca include swelling, redness, pain or itch at the injection site, joint pain and malaise (feeling unwell). Less common side effects include abdominal pain, dizziness, decreased appetite, pain in limb or enlarged lymph nodes. These side effects are experienced in up to two-thirds of people who receive this vaccine, and mostly resolve within 1-2 days. Symptomatic relief is recommended, i.e. a cool compress at the injection site and simple analgesia such as paracetamol or ibuprofen.

Rare side effects include anaphylaxis and a rare clotting condition, thrombosis with thrombocytopenia (TTS). Symptoms of TTS may include a severe, persistent headache that does not settle with analgesia, abdominal pain, significant respiratory problems/distress, visual changes, vomiting, seizures, focal neurological deficits/changes, confusion/encephalopathy and usually occur 4-20 days after vaccination.

Comirnaty™ (Pfizer/BioNTech) side effects

Common side effects following vaccination with Comirnaty™ include swelling or pain at the injection site, fatigue, headache, myalgia (body aches), fever, chills or joint pain.

Less common side effects include redness or itching at the injection site, nausea, enlarged lymph nodes, malaise (feeling unwell), pain in limb or insomnia. These side-effects are usually mild and last 1-2 days and may require time off work. Systemic reactions are more common following the second dose of the vaccine. Symptomatic relief is recommended, eg. a cool compress at the injection site and simple analgesia such as paracetamol or ibuprofen.

Very rarely, anaphylaxis following Comirnaty™ has been reported.

Can a patient be referred to a specialist immunisation clinic after experiencing AEFI?

The VicSIS network will provide specialist vaccination services for people who have experienced an AEFI with a COVID-19 vaccine, or those who are identified as at risk of an AEFI (for example, people with a history of anaphylaxis). Most people are able to proceed with future vaccines following an AEFI. Clinical consults will be offered in which individual recommendations will be developed. VicSIS clinics will have the ability to vaccinate under extended observation.

For more information on how to refer to VicSIS, please refer to MVEC: The VicSIS (Victorian Specialist Immunisation Services) Network.

Resources

Authors: Francesca Machingaifa (MVEC Education Nurse Coordinator) and Georgina Lewis (SAEFVIC Clinical Manager, Murdoch Children's Research Institute)

Date: April 2021

Materials in this section are updated as new information and vaccines become available. The Melbourne Vaccine Education Centre (MVEC) staff regularly reviews materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family’s personal health. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult a healthcare professional.

 

 

 

 

 

 

 

 


COVID-19 weekly vaccine updates

Background

Since the emergence of SARS-CoV-2 in late 2019, COVID-19 has taken a huge toll globally with over 100 million cases and 2.5 million deaths, as well as long term health impacts and the wide ranging consequences of lockdowns. The rapid development of multiple vaccines globally has been a tremendous success story for public health. However, it can prove challenging to stay up to date with the increasing literature on various aspects of these vaccines. The COVID-19 weekly vaccine update summarises the data available on COVID-19 vaccines and includes: the specifications of COVID-19 vaccines, vaccine efficacy and effectiveness including against variants of concern; comorbidities and the elderly; vaccine safety; the pipeline for vaccine development; and the WHO SAGE timeline for vaccine authorisation. Each week, the document is updated and contains newly released information on the vaccines.

Who we circulate to and why

The document was compiled in collaboration with the WHO South Pacific Division of Pacific Technical Support (DPS). The main target audience is government of Pacific Islands countries, WHO country offices, UNICEF and development partners. The distribution list includes many individuals working in public health, public health associations and media organisations.

To subscribe, email kase.anderson@unimelb.edu.au

Alternatively you can access the update (as well as the historical versions) via COVID-19 weekly vaccine update.

Who the authors are

The document is compiled by Dr John Hart, a research clinician at MCRI. Expert oversight is provided by Professor Fiona Russell and Professor Kim Mulholland. Fiona Russell is Senior Principal Research Fellow, Centre for International Child Health, The University of Melbourne; and Group Leader, Asia-Pacific Health, MCRI; and sits on the WHO DPS Joint Incident Management Team COVID-19 Vaccine Pillar group to provide technical support for Pacific Island Countries. Kim Mulholland is Professor of Child Health and Vaccinology at the London School of Hygiene and Tropical Medicine; and Professorial Fellow at MCRI. Quality checks are conducted by Professor Julie Bines, Associate Professor Nigel Crawford and Associate Professor Margie Danchin. Julie Bines leads the RV3 Rotavirus Vaccine Program and is the inaugural Victor and Loti Smorgon Professor of Paediatrics and Deputy Head of Department of Paediatrics at the University of Melbourne. Nigel Crawford is director of SAEFVIC (Surveillance of Adverse Events Following Vaccination in the Community), a vaccine safety and clinical immunisation research group based at MCRI. Margie Danchin has extensive experience in vaccine research and is Group Leader, Vaccine acceptance, Uptake and Policy, at MCRI.

Authors: Dr John Hart (Research Clinician, Murdoch Children’s Research Institute)

Date: March 2021

Materials in this section are updated as new information and vaccines become available. The Melbourne Vaccine Education Centre (MVEC) staff regularly reviews materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family’s personal health. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult a healthcare professional.


COVID-19 vaccines and allergy

Background

Hypersensitivity/allergic reactions following immunisation can be classified as:

  • Urticarial – a red, itchy skin rash often referred to as hives, which characteristically has a central raised white wheal surrounded by an area of redness
  • Non-urticarial rash – skin changes that don’t involve hives
  • Angioedema – swelling in the deeper layers of the skin
  • Generalised allergic reaction – involving symptoms like vomiting and diarrhoea
  • Anaphylaxis – a sudden onset and rapid progression of symptoms involving the skin, as well as systemic symptoms respiratory and/or cardiovascular systems

Suspected hypersensitivity reactions, particularly non-urticarial skin rashes following immunisation, are common, however true vaccine allergy, where a person is contraindicated from being immunised with the same vaccine in the future, is rare (in most studies reported as less than 1 case per million doses). For further information on diagnosing hypersensitivity reactions and anaphylaxis please refer to Guidance for differentiating anaphylaxis from acute stress response for vaccine providers and Emergency Departments.

Post-licensure surveillance of COVID-19 vaccines show anaphylaxis following administration of COVID-19 AstraZeneca occurring at similar rates to routine vaccines [refer to TGA: AstraZeneca ChAdOx1-S COVID-19 vaccine].  Anaphylaxis following Comirnaty™ (Pfizer/BioNTech), whilst still extremely rare, occurs at a slightly higher rate of approximately 4.7 cases per million doses.

A confirmed vaccine allergy usually requires a specialist consultation with a vaccine allergy specialist, often with specific testing or a vaccine challenge under supervision.

All COVID-19 immunisation hypersensitivity/allergic reactions should be reported to your state’s vaccine safety reporting service. In Victoria this is SAEFVIC. SAEFVIC staff may direct the report to an Immunisation Specialist or alternatively to a Vaccine Allergy Specialist within the VicSIS network (a network of specialist immunisation clinics in Victoria), as appropriate.

Allergy to components of COVID-19 vaccines

Polyethylene Glycol (PEG)

PEG is an ingredient contained in Comirnaty™. It is also a commonly used ingredient of other medications, hand sanitisers, cosmetics, bathroom products and colonoscopy preparation products, routinely used within Australia. Whilst it is uncertain whether PEG contained in mRNA vaccines may trigger anaphylaxis, additional precautions are required prior to administration.

It is recommended people with a history of confirmed or suspected allergy to PEG seek specialist advice from an immunology/allergy/vaccination specialist regarding the safety of receiving an mRNA COVID-19 vaccine.

NB: Vaccination with the Comirnaty™ COVID-19 vaccine is contraindicated in people with documented anaphylaxis to PEG.

Polysorbate 80

Polysorbate 80 is chemically related to Polyethylene Glycol and is an ingredient in COVID-19 AstraZeneca vaccine.

If there is a history of confirmed or suspected allergy to Polysorbate 80 it is recommended that specialist advice be sought from an immunology/allergy/vaccination specialist regarding the safety of administering COVID-19 AstraZeneca.

NB: Vaccination with the COVID-19 AstraZeneca vaccine is contraindicated in people with documented anaphylaxis to Polysorbate 80.

Latex

The COVID-19 vaccines with provisional registration for use within Australia (Comirnaty™ and COVID-19 AstraZeneca vaccine) can both be administered to people with latex allergies following standard precautions, with a 15-minute post-vaccination observation period. Neither Comirnaty™ or COVID-19 AstraZeneca vials contain latex.

COVID-19 vaccines and allergies

Reaction following a previous dose of a COVID-19 vaccine

The only two absolute contraindications to vaccination are anaphylaxis to a previous dose of the same vaccine or anaphylaxis to a component of the vaccine.

Additional precautions are recommended for individuals with possible allergic reactions to a previous dose of a COVID-19 vaccine. In this instance, a specialist review by an immunology/allergy/vaccination specialist to undertake a risk/benefit assessment to assess suitability for further vaccination should be undertaken.

If an individual experiences anaphylaxis after being vaccinated with one type of COVID-19 vaccine, this does not preclude them from having another type following the additional precautions above. If there is a high risk of an allergic reaction to one of the COVID-19 vaccines due to an existing allergy to PEG or Polysorbate 80 it may be possible to a have a COVID-19 vaccine that does not contain the ingredient, depending on availability and with appropriate medical advice.

COVID-19 vaccination in people with allergic conditions

For patients with a history of anaphylaxis to food, drugs, venom or latex, it is recommended a routine observation period of 15 minutes following COVID-19 vaccination is observed.

If there is a history of a known systemic mast cell activation disorder with raised mast cell tryptase that has required treatment, additional precautions are recommended. Following consultation with an immunology/allergy/vaccination specialist to undertake a risk/benefit assessment to assess suitability for vaccination should be undertaken. Immunisation in a medical facility with a 30-minute observation period may be recommended.

Please refer to COVID-19 vaccination – ATAGI clinical guidance on COVID-19 Vaccine in Australia in 2021 or the ASCIA Allergy, Immunodeficiency, Autoimmunity and COVID-19 Vaccination Position Statement for more information.

Management following anaphylaxis to a COVID-19 vaccine

Should symptoms of anaphylaxis occur immediate treatment should be provided [refer to Australian Immunisation Handbook: Adverse events following immunisation]

Investigations

Tryptase levels are recommended following potential allergic reactions as they assist with allergy assessment. Normal tryptase levels are reassuring. Tryptase levels are recommended 1 hour, 4 hours and 24 hours post reaction, however, if this is not possible, it recommended once an individual presents to an emergency department and is stable and then just prior to discharge in the case of a short admission.

It is recommended that EpiPens only be prescribed by an allergy/immunology specialist following a review. This is based on the following:

  • Vaccines can be easily avoided and EpiPens are on the Pharmaceutical Benefits Scheme for indications that cannot be avoided
  • A prescription of an EpiPen has been shown to increase anxiety in people once it is prescribed even if it is not clinically indicated, which is thought to be due to the perceived uncertainty of future reactions.

Resources:

Authors: Rachael McGuire (MVEC Education Nurse Coordinator), Nigel Crawford (Director, SAEFVIC, Murdoch Children's Research Institute), Daryl Cheng (Paediatrician, The Royal Children’s Hospital), Francesca Machingaifa (MVEC Education Nurse Coordinator), Sara Barnes (Head of Allergy, Monash Health) and Adele Harris (Research Nurse, SAEFVIC, Murdoch Children's Research Institute)

Date: March 2021

Materials in this section are updated as new information and vaccines become available. The Melbourne Vaccine Education Centre (MVEC) staff regularly review materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family’s personal health. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult a healthcare professional.

 

 

 

 

 

 

 

 

 

 


Chickenpox

What is it?

Varicella (chickenpox) is a highly contagious infection caused by the varicella-zoster virus (VZV).

What to look for

Infection usually begins with 1-2 days of fever, runny nose and lethargy.

An itchy rash follows, involving fluid filled vesicles (blisters) that can cover any part of the body including inside the mouth, eyelids and genital area. Severe complications can include pneumonia, meningitis and encephalitis.

Varicella in pregnancy can result in skin scarring, ocular anomalies, limb defects and neurological malformations for the infant.

The virus can be reactivated later in life and cause Zoster (Shingles).

How is it transmitted?

Varicella can be transmitted by coughing or sneezing, or from direct contact with the fluid inside the vesicles.

Prevention

Immunisation is the most effective form of prevention. A single dose of the live-attenuated vaccine is currently funded on the National Immunisation Program (NIP) for children at age 18 months of age, however giving a 2nd dose (not funded) provides greater protection. For those ≥ 14 years of age, 2 doses (administered 4 weeks apart) are required for the protection on non-immune individuals.

Post-exposure prophylaxis

If a non-immune individual is exposed to disease, immunisation is recommended within 3-5 days (provided immunisation is not contraindicated). This can reduce the likelihood of varicella infection developing.

Neonates (whose mother develops infection up to 7 days prior to delivery or within 2 days after delivery), infants < 1-month of age (if mother is seronegative), pregnant women, premature infants (while still hospitalised, regardless of maternal serology) or immunosuppressed individuals who are exposed to varicella disease should receive Zoster Immunoglobulin (ZIG).

Repeat doses of ZIG may be given if a person is exposed to varicella again > 3-weeks after the first dose of ZIG.

Resources

Author: Rachael McGuire (Research Nurse, SAEFVIC, Murdoch Children's Research Institute)

Reviewed by: Rachael McGuire (Research Nurse, SAEFVIC, Murdoch Children's Research Institute)

Date: July 2020

Materials in this section are updated as new information and vaccines become available. The Melbourne Vaccine Education Centre (MVEC) staff regularly reviews materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family's personal health. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult a healthcare professional.


COVID-19 vaccine candidate: Novavax

Name: NVX-CoV2373

Type: Protein vaccine (nanoparticle-based vaccine)

Developer: Novavax

Likely doses/timing: 2 doses (21 days apart)

Doses for Australia: 51 million doses will be made available in Australia during 2021

Manufacturing: Doses for Australia will be manufactured in several locations across Europe and Asia

Storage: Can be stored, transported and handled at standard refrigerator temperatures (2-8°C)

Background

The Novavax COVID-19 vaccine (NVX-CoV2373) was created using Novavax’ recombinant nanoparticle technology which contains the full length SARS-CoV-2 spike protein and Novavax’ patented Matrix-M1 adjuvant (an additional vaccine component that boosts the immune response).

Novavax is a biotechnology company from the USA. Their nanoparticle and Matrix-M1 technology has been previously studied in Phase 3 trials of their quadrivalent influenza vaccine, NanoFlu.

Clinical trials

Pre-clinical trials were conducted in baboons and mice. In animal models, the vaccine induced high levels of anti-spike antibodies and neutralising antibodies, which exceeded the responses measured in humans recovered from natural COVID-19 infection.

Phase 1 clinical trials were conducted in 131 healthy adults, beginning in May 2020. Early clinical trials were performed in Melbourne and Brisbane, Australia, as well as in the USA. Phase 1 results were released in September 2020. This study assessed the safety and immunogenicity of two doses (5-μg and 25-μg) with or without Matrix-M1 adjuvant in healthy adults aged 18 to 59 years, compared to placebo. The phase 2 clinical trials expanded the age of participants to include those aged 60-84 years and results are still pending.

Phase 3 trials are underway in the UK and enrolment of 15,000 participants was completed in November 2020. Interim data is expected in the first quarter of 2021. More large-scale clinical trials are underway or planned for other countries in late 2020 and early 2021, including South Africa, USA and Mexico. These Phase 3 trials will include 30,000 participants overall.

Safety profile

No serious adverse events or adverse events of special interest were reported in Phase 1 trials. Overall reactogenicity was largely absent or mild and the average duration was two days or less for both doses. After first vaccination, local reactions only occurred in 4-16% of participants that received NVX-CoV2373 (the rate of reaction varied for each subgroup; depending on dose given or whether adjuvant was given). Systemic reactions occurred in 4-32% of participants, depending on the subgroup. Common side effects included headache, fatigue and myalgia. After the second vaccination, local and systemic reactogenicity were absent or mild in the majority of participants in all subgroups.

Immunogenicity

Phase 1 results showed NVX-CoV2373 elicited robust antibody responses which were greater than the responses measured in people recovered from natural COVID-19 infection. All participants developed antibodies after a single dose. All participants developed neutralizing antibodies after the second dose. The Matrix-M1 adjuvant was dose sparing; in those receiving NVX-CoV2373 with the Matrix-M1 adjuvant, immunogenicity results were comparable in both low and high dose groups. The Matrix-M1 adjuvant also induced robust polyfunctional CD4+ T-cell responses.

Vaccine efficacy

Interim data regarding vaccine efficacy from the UK’s Phase 3 trials are expected in the first quarter of 2021, noting the high rates of COVID-19  being seen globally may lead to early completion of these event driven trials.

Resources

Authors: Daniela Say (MVEC Immunisation Fellow) and Nigel Crawford (Director SAEFVIC, Murdoch Children’s Research Institute)

Date: January 2021

Materials in this section are updated as new information and vaccines become available. The Melbourne Vaccine Education Centre (MVEC) staff regularly reviews materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family’s personal health. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult a healthcare professional.

 

 

 

 

 

 

 


Comirnaty™

Name: BNT162b2

Type: Genetic vaccine (messenger RNA/mRNA)

Developer: Pfizer/BioNTech

Likely doses/timing: 2 doses (21 days apart)

Doses for Australia: 10 million doses will be available from early 2021

Manufacturing: Doses for Australia will be manufactured overseas

Storage: Must be stored at ultra-cold temperatures of -90°C to -60°C. Unopened vials can be stored and transported at domestic freezer temperatures (-25°C to -15°C) for up to 2 weeks. Vials stored or transported at domestic freezer temperatures can be returned to ultra-cold longer term storage within the original shelf life of the product. Unopened vials can be stored for up to 5 days at temperatures of 2°C to 8°C. Once thawed, Comirnaty™ cannot be refrozen.

Preparation and Injection: Each multi-dose vial of the vaccine contains 5 doses of 0.3ml. The vaccine must be thawed before injection and diluted with the recommended diluent. After dilution the vial must be used within six hours. The vaccine is administered intramuscularly (IM).

Background

Pfizer/BioNTech’s COVID-19 vaccine (BNT162b2) has been issued Emergency Use Authorization (EUA) and even full approval in several counties. Of note, the UK and USA have both issued an EUA, on 2 December and 11 December 2020, respectively. The first injections under a country-wide program began in the UK on 8th  December 2020.

Pfizer’s BNT162b2 vaccine contains messenger RNA (mRNA) which codes for the SARS-CoV-2 full-length spike protein. Although mRNA vaccines have never been licensed before, they had already been studied for more than a decade. mRNA vaccines were already under development for other viruses, such as influenza, and have been tested and shown to be safe in previous clinical trials.

On 25 January 2021, the Pfizer/BioNTech COVID-19 vaccine (Comirnaty) was the first COVID-19 vaccine to be granted provisional registration in Australia.

Clinical trials

Pre-clinical trials were conducted in non-human primates (rhesus macaques) and mice. In animal models, the vaccine induced a strong immune response and prevented lung infection. Vaccinated primates, who were challenged with SARS-CoV-2 virus, had no virus detected in the lower respiratory tract and clearance of virus in the nose within three days. These results indicated the vaccine may reduce both infection and transmission.

Phase 1/2 clinical trials were conducted in Germany and USA. The US Phase 1 trial also included older participants (up to 85 years old) and compared placebo to one of two vaccine candidates (BNT162b1, which encoded the SARS-CoV-2 receptor-binding domain; or BNT162b2, which encodes the SARS-CoV-2 full-length spike). This trial supported the selection of BNT162b2 for advancement to Phase 2/3 trials.

Phase 2/3 clinical trials of BNT162b2 were conducted across USA, Germany, Argentina, Brazil, South Africa and Turkey, and started in July 2020. Initial results of the Phase 3 trial from 43,448 participants, aged 16 years or older, were published in the New England Journal of Medicine on 10 December 2020.

Safety profile

The reactogenicity of BNT162b2 was generally mild or moderate, reactions were generally short-term and were less common and milder in older adults, compared to younger adults. Systemic reactions were more common and severe after the second dose. The incidence of serious adverse events was low and similar in both the vaccine and placebo groups. Phase 3 trial results were consistent with earlier clinical studies and provided results from a median follow-up time of two months after the second dose.

Mild-to-moderate pain at the injection site within seven days after an injection was the most commonly reported local reaction (66-83% depending on age group or first versus second dose). Pain resolved within 1-2 days, there was no increase in reported local reactions after the second dose and no reactions required emergency department visit or hospitalisation.

The most commonly reported systemic events were fatigue (59%), headache (52%) and muscle aches (37%), after the second dose among younger vaccine recipients. These proportions were lower in older vaccine recipients; 51% with fatigue, 39% with headache and 29% with muscle aches after the second done. Severe systemic events were reported in less than 2% of vaccine recipients after either dose, except for fatigue (in 3.8%) and headache (in 2%) after the second dose.

In younger vaccine recipients, fever (≥ 38°C) was reported in 4% after the first dose and 16% after the second dose. In older recipients, fever was reported in 1% and 11%; after first and second dose respectively. Systemic events including fever and chills were observed within the first 1-2 days after vaccination and resolved shortly thereafter.

Serious adverse events were rare; only four were reported among BNT162b2 recipients (shoulder injury related to vaccine administration, right axillary lymphadenopathy, paroxysmal ventricular arrhythmia, and right leg paraesthesia). No stopping rules (trial pauses) were met during the reporting period. Safety monitoring for this vaccine will continue for 2 years after administration of the second dose of vaccine.

Since public vaccinations began in December 2020, anaphylactic reactions in people receiving the Pfizer/BioNTech COVID-19 vaccine have been reported in the United Kingdom and United States. Clear guidance regarding allergy management will be provided once the Pfizer/BioNTech vaccine has regulatory approval from the TGA. Some guidance from the CDC is included in the following links:

  1. Allergic Reactions Including Anaphylaxis After Receipt of the First Dose of Pfizer-BioNTech COVID-19 Vaccine — United States, December 14–23, 2020
  2. Interim Clinical Considerations for Use of mRNA COVID-19 Vaccines Currently Authorized in the United States
  3. Lab Tests to Collect Shortly After Severe Allergic Reaction/Anaphylaxis Following COVID-19 Vaccination.

Immunogenicity

Two doses of BNT162b2 elicited high SARS-CoV-2 neutralising antibody titres and robust spike protein-specific T-cell responses. These neutralising antibody responses were greater than the responses measured in people recovered from natural COVID-19 infection; in both younger and older adults. The duration of protection is currently unknown, with booster doses not recommended at this stage.

Vaccine efficacy

The Pfizer/BioNTech vaccine was the first to present interim data of their Phase 3 trial, indicating the vaccine had 95% vaccine efficacy. Similar vaccine efficacy (generally 90 to 100%) was observed across all subgroups defined by age, sex, race, ethnicity, baseline body-mass index, and the presence of co-existing conditions. Older adults, 65 years and over, also had the same vaccine efficacy as younger adults.

In among 36,523 participants who had no evidence of existing or prior SARS-CoV-2 infection, there were only 8 cases of COVID-19 (with onset at least seven days after the second dose) in those vaccinated with BNT162b2, compared to 162 cases of COVID-19 among those who received placebo. This corresponded to 95% vaccine efficacy. When combined with participants who did have evidence of past SARS-CoV-2 infection, the vaccine efficacy was still similar (94.6%).

The vaccine appears likely to provide individual protection and prevent severe disease; among 10 cases of severe COVID-19 with onset after the first dose, 9 occurred in placebo recipients and 1 in a BNT162b2 recipient.

Less than two weeks after the first dose, the vaccine started protecting participants, and the second dose three weeks later, boosted their immune response. The study was not designed to assess the efficacy of a single-dose regimen, however, in the interval between the first and second doses, the observed vaccine efficacy against COVID-19 was 52%, reaching full efficacy at least seven days after the second dose.

Ongoing research

Phase 3 trials are still ongoing and safety monitoring for this vaccine will continue for two years after administration of the second dose of vaccine. Safety monitoring will also continue in the post-licensure phase through surveillance of adverse events following immunisation reporting systems.

Further Phase 3 trials are underway or planned in children (underway for adolescents 12 years and older and planned for younger children), pregnant women and special risk groups, such as immunocompromised people.

Ongoing data collection is required to assess whether the vaccine prevents transmission and asymptomatic cases, as well as assessing how long immune memory may last and whether booster doses are required.

This vaccine has not yet been assessed in clinical trials when co-administered with other vaccines; hence the vaccine should be administered alone. The USA’s CDC recommends a minimum interval of 14 days before or after administration with any other vaccines, including seasonal influenza. ATAGI recommends a 14 day minimum interval between the administration of influenza and COVID-19 vaccines [refer to: ATAGI advice on influenza and COVID-19 vaccines].

Resources

Authors: Daniela Say (MVEC Immunisation Fellow) and Nigel Crawford (Director SAEFVIC, Murdoch Children’s Research Institute)

Reviewed by: Francesca Machingaifa (MVEC Education Nurse Coordinator)

Date: 21 April 2021

Materials in this section are updated as new information and vaccines become available. The Melbourne Vaccine Education Centre (MVEC) staff regularly reviews materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family’s personal health. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult a healthcare professional.

 

 


COVID-19 AstraZeneca

Name: COVID-19 AstraZeneca Vaccine (AZD1222 or ChAdOx1 nCoV-19)

Type: Viral vector vaccine (chimpanzee adenovirus vector)

Developer: AstraZeneca

Recommended doses/interval: 2 doses, administered 12 weeks apart (noting a minimum interval of 4 weeks is acceptable)

Doses for Australia: 53.8 million doses, 3.8 million doses from overseas scheduled for delivery to Australia

Manufacturing: 50 million doses will be manufactured in Parkville, Australia in monthly batches by local biotechnology company, CSL

Storage: Can be stored, transported and handled at standard refrigerator temperatures (2-8°C)

Background

The COVID-19 AstraZeneca vaccine utilises a chimpanzee adenovirus (ChAdOx1) vector; which is unable to cause disease in humans. This viral vector has been tested for safety in other vaccines for Ebola, Middle East respiratory syndrome (MERS) and influenza. This vaccine utilises the full length SARS-CoV-2 spike protein DNA inserted into the viral vector.

On 16 February 2021, the University of COVID-19 AstraZeneca was granted provisional registration in Australia by the Therapeutic Goods Administration for use in those ≥ 18-years of age for the prevention of COVID-19 disease caused by SARS-CoV-2.

UPDATE: On April 8th 2021, following reported cases of thrombosis with thrombocytopenia syndrome (TTS) after administration of the COVID-19 AstraZeneca, it is no longer the preferred vaccine for those aged < 50 years in Australia.

Clinical trials

Pre-clinical (animal) trials were conducted in rhesus macaques, mice and ferrets. These trials showed that there were no adverse safety events, no evidence of immune enhanced inflammatory disease and a balanced immune response was induced. In animals, the vaccine appeared to reduce disease severity, but did not prevent infection or transmission (nasal shedding of the virus still occurred).

Phase 1/2 clinical trials were conducted in UK and recruited over one thousand participants in April and May 2020. Phase 2/3 clinical trials are being conducted in 50,000 participants globally (UK, USA, Brazil, South Africa and Kenya), with recruitment starting in July 2020.

Interim results of Phase 3 studies, from over 10,000 participants in the UK, Brazil and South Africa, were published in the Lancet on 8 December 2020. In participants who received two standard doses, vaccine efficacy was 62·1% and in participants who received a low dose followed by a standard dose, efficacy was 90%. Overall vaccine efficacy across both groups was 70·4%.

Primary results from a further phase 3 US trial including 32,449 participants were released by AstraZeneca on 22 March 2021. The vaccine demonstrated efficacy of 76% against symptomatic disease and 100% efficacy against severe or critical disease and hospitalisation. These results were consistent across age groups, with vaccine efficacy of 85% in people aged over 65-years. These results are currently undergoing peer review.

Safety profile

Phase 1/2 results showed that the vaccine was safe but had higher reactogenicity than the control vaccine. Symptoms mainly occurred in the day following vaccination and self-resolved. Pain and tenderness at the injection site (83%), fatigue (68%) and headache (70%) were the most common symptoms in participants receiving COVID-19 AstraZeneca. Fever occurred in 18% and flu-like symptoms of malaise (61%) and muscle ache (60%) were also common.

Phase 2/3 results showed similar reactions to those seen in Phase 1/2 trials but reactions were less common in older adults (aged over 55-years) and after the second dose. Most of the reported local and systemic adverse events were mild to moderate in severity.

Of the nearly 24,000 trial volunteers, only three of the 175 reported serious adverse events were possibly related to the vaccine and more than half of these events occurred in the control arm.

There have been two trial pauses due to initially unexplained illnesses; these were reviewed by independent experts before restarting the trials. One case of transverse myelitis was reported two weeks after COVID-19 AstraZeneca booster vaccination and was possibly related to vaccination. There were two additional cases of transverse myelitis that were determined to be unlikely to be related to vaccination by an independent committee of neurological experts. One case was due to pre-existing, but previously unrecognised, multiple sclerosis and the second case occurred in the control arm.

Primary results from the Phase 3 US trial showed that the COVID-19 AstraZeneca was well tolerated, and no safety concerns related to the vaccine were identified. The results are currently undergoing peer review.

Post-licensure surveillance

An independent expert review of 7 reported cases in Australia of suspected anaphylaxis following administration of the COVID-19 AstraZeneca vaccine has concluded that there is no increased risk of anaphylaxis associated with the vaccine above the expected rate for any other vaccine. Anaphylaxis is a very rare side effect that can occur with any vaccine.

A rare but serious clotting disorder known as ‘thrombosis with thrombocytopenia syndrome (TTS)’ has been seen in a very small number of people who have received the COVID-19 AstraZeneca vaccine in Australia, the UK and Europe. The vaccine appears likely to be causally-linked with a risk of this newly recognised syndrome.

Secondary to these cases, and as a ‘highly precautionary measure’, on April 8th 2021 the Australian Government announced that Australians under 50 should preferentially receive other vaccines (such as Pfizer) over the COVID-19 AstraZeneca vaccine. This decision is based on three recommendations from the Australian Technical Advisory Group on Immunisations (ATAGI):

  • Pfizer (or other) vaccines preferred over COVID-19 AstraZeneca in those under the age of 50
  • People under 50 who have had their first dose of COVID-19 AstraZeneca vaccine without side effects can have their second dose
  • People over 50 should receive the COVID-19 AstraZeneca vaccine

Further information can be accessed via ATAGI: Statement on AstraZeneca vaccine in response to new safety concerns.

COVID-19 AstraZeneca is still strongly encouraged for Australians aged 50 and over and is highly effective at preventing severe COVID.

COVID-19 AstraZeneca can be given to people aged under 50 where benefits are likely to outweigh the risks and an individual has made an informed decision based on an understanding of the risks and benefits. The Department of Health have released a document entitled Weighing up the potential benefits against risk of harm from COVID-19 AstraZeneca which provides information to assist individuals in making an informed decision about whether or not to be vaccinated with COVID-19 AstraZeneca.

For more information please refer to our COVID-19 frequently asked questions on COVID-19 AstraZeneca.

Resources

Authors: Daniela Say (MVEC Immunisation Fellow) and Nigel Crawford (Director SAEFVIC, Murdoch Children’s Research Institute)

Reviewed by: Daryl Cheng (Paediatrician, Royal Children's Hospital), Davina Buntsma (MVEC Immunisation Fellow), Rachael McGuire (MVEC Education Nurse Coordinator) and Francesca Machingaifa (MVEC Education Nurse Coordinator)

Date: 19th April 2021

Materials in this section are updated as new information and vaccines become available. The Melbourne Vaccine Education Centre (MVEC) staff regularly reviews materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family’s personal health. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult a healthcare professional.

 

 

 

 

 

 

 


COVID-19 vaccines: frequently asked questions

MVEC’s COVID-19 vaccine FAQ’s have been designed to address common queries relating to COVID-19 vaccines. For ease of reference, information has been categorised as per the below themes:

This page will be updated on a regular basis as further information becomes available regarding COVID-19 vaccines.

For questions that have not been addressed on this page or our dedicated COVID-19 resource page, please email info.mvec@mcri.edu.au for further clarification.

Vaccine development process

  • How can the COVID-19 vaccine be safe when it has been developed so quickly?

    COVID-19 vaccine development is happening “faster than usual” because of the global impact of the pandemic and the urgent need for a vaccine(s). Vaccines have traditionally been developed in consecutive sequential stages – with preclinical trials followed by phases I, II and III, often with large gaps of time in-between phases awaiting funding or manufacturing scaleup. With COVID-19, this process has been made more efficient by running one phase while simultaneously also preparing and/or recruiting for the next phase.

    It is important to note that COVID-19 vaccine candidates must pass through the exact same rigor and phases of clinical trials and do not miss any important safety and quality checks or steps. Approval is only given if the vaccine meets the appropriate requirements for safety and efficacy.

    Refer to MVEC: Vaccine development and safety, including “The Road to a COVID-19 Vaccine” animation for more information.

  • What is involved in the phases of clinical trials?

    During vaccine development, initial safety testing of a vaccine candidate occurs in two stages. Stage one involves preclinical assessment both in the laboratory and also animal trials.  Stage two involves the evaluation of the vaccine candidate in three phases of clinical trials in human volunteers.

    Phase I clinical trials: the vaccine candidate is given to small numbers (25–50) of healthy adults with the primary goal of assessing safety.

    Phase II clinical trials: If the vaccine candidate is found to be safe in Phase I, it is then given to hundreds of participants to determine: how effectively it stimulates immune responses; optimal dose regimen; and whether its side effect profile.

    Phase III clinical trials: If the vaccine candidate is found to be effective and safe in both Phase I and II, it is then given to many thousands of participants to test its effect on protecting large populations from the target disease and to determine if there are any uncommon, serious or severe side effects.

    Refer to MVEC: Vaccine development and safety for more information.

  • What does provisional approval mean and how does it differ from normal registration?

    In Australia, the Therapeutic Goods Administration (TGA) is responsible for assessing vaccines and other medicines for use in Australia. A number of sponsors of COVID-19 vaccines have applied to the TGA for registration using the so-called ‘provisional approval pathway’.

    The provisional pathway is only one of a number of pathways that a sponsor may use to apply for the approval of a vaccine. It is very important to note that the TGA evaluation process under the ‘provisional pathway’ still involves a full review of the vaccine and its associated safety data, noting that the TGA does not have a mechanism for emergency use authorisations (EUA) that have been granted in other countries. The provisional approval is for an initial period of 2 years. Sponsors may then apply for ‘full registration’ when there is more clinical data to confirm the safety of the vaccine.

    Refer to MVEC: Provisional registration of COVID-19 vaccine(s) in Australia for more information on provisional approval.

    Refer to TGA: COVID-19 vaccines for further information on the role of the TGA and their internal processes.

  • How can we be sure that the vaccine manufacturing process is safe?

    Like any medication in development, vaccine candidates must undergo rigorous testing procedures and scientific evaluation to prove not only their effect on the targeted disease, but also to determine their safety – before being licensed and registered for use in vaccination programs.

    In all three clinical trial phases, safety is continually assessed as data is gathered and a vaccine must pass all these phases before it can be considered for registration for use by the TGA. By the time a vaccine is registered, safety would have been assessed in tens of thousands of clinical trial participants and this safety data would have been rigorously evaluated by the TGA and other international drug regulatory bodies.

    The quality, sterility, potency and purity of each vaccine batch is also assessed by the TGA prior to being supplied to Australia, as is the quality of selected batches after they have been supplied.

    Once a vaccine is approved, it continues to be tested in a process known as post-licensure surveillance.

  • Who funds a vaccine trial?

    Vaccine research and development is often funded by a range of sources including governments, bilateral and multilateral organisations, non-government organisations and the private sector (including pharmaceutical companies). Never before has one vaccine received so much investment and global collaboration – this is a major reason why there are multiple COVID-19 vaccines that have been able to progress so efficiently with minimal pauses through to the final phase III large clinical trials.

    A prominent funding source for many COVID-19 vaccines is the COVAX Facility. COVAX is coordinated by Gavi (the Vaccine Alliance), the Coalition for Epidemic Preparedness Innovations (CEPI) and the World Health Organization. COVAX pools funding from over 180 governments, global health organisations, private sector and manufacturers to support research, development and manufacturing of multiple COVID-19 vaccine candidates.

    Refer to MVEC: COVAX Facility for more information about COVAX.

Vaccine rollout

Effectiveness

  • How do we know a vaccine is effective?

    In vaccine clinical trials it is important to understand the difference between efficacy versus effectiveness. Efficacy is calculated from a Phase III clinical trial and effectiveness is the vaccine’s impact in a real world setting once the vaccine is administered in the general public.

    Vaccine clinical trials represent a strictly controlled setting; for example, trial participants are closely monitored and if two vaccine doses are required, the doses will be given with exactly the same interval for everyone. All vaccines that are eventually registered will have proved they have adequate efficacy through large Phase III trials.

    Efficacy is calculated by assessing how many people develop COVID-19 in the group receiving the COVID-19 vaccine compared to the placebo (or control) group. For example, if 100 people develop COVID-19 disease in a trial, and 95 of these were in the placebo group (meaning only 5 people in the vaccine group developed disease), the vaccine efficacy would be calculated at 95%. In other words, the vaccine prevented 95 out of 100 people from contracting COVID-19 disease. Efficacy is usually calculated after the full vaccine course; for most COVID-19 vaccines this is after two doses.

    In a real-world setting, it is expected that there will be lower levels of protection due to multiple variables, such as wider differences amongst people receiving the vaccine (eg. different ethnicities or underlying medical conditions). Hence vaccine effectiveness is expected to be slightly lower than what is reported in initial clinical trial results. Vaccine effectiveness in the real world will continue to be monitored in post-licensure studies.

  • Is vaccine efficacy the same in all ages?

    Each vaccine is tested in multiple age groups because efficacy can vary amongst different ages. Currently, efficacy data is only available for people ≥16 years of age for  Comirnaty™ (Pfizer/BioNTech COVID-19 vaccine) and ≥18 years for the other vaccines. Further Phase III trials are underway or planned in children, starting with adolescents and progressing to younger ages as more safety data becomes available. Until then, COVID-19 vaccines have only been licensed for children above 16 years of age in Australia.

    Depending on the specific vaccine candidate, the vaccine’s efficacy may also be reduced for people over 65 years of age. With aging, the immune system progressively declines, referred to as immunosenescence, and hence there may be a reduced immune response following vaccination in older adults. Clinical trials for COVID-19 AstraZeneca vaccine demonstrated an excellent safety profile and strong immune response in those aged >65 years, however efficacy in this age group could not be conclusively determined due to an insufficient number of participants infected with SARS-CoV-2. As a result, the TGA recommend that immunisation with COVID-19 AstraZeneca in this age group be decided on a case-by-case basis taking into account age, co-morbidities and environmental factors. Further information from ongoing clinical trials is expected in the coming months.

  • Are there certain vaccine brands that are better for people over 65 years of age?

    Some of the COVID-19 vaccines, such as the  Comirnaty™ (Pfizer/BioNTech COVID-19 vaccine), have the same efficacy in older adults, aged 65 years and over, compared with younger adults. Others, such as the COVID-19 AstraZeneca vaccine, are still gathering further data in order to accurately assess vaccine efficacy in older age groups (over 55 years). However, their immunogenicity studies show that older adults develop a robust immune response, similar to those seen in younger volunteers. In time, more efficacy data will be available for older age groups for all vaccines.

  • Will the vaccine be effective in children?

    At this stage, there is no clinical trial data for children younger than 16 years of age and currently, none of the COVID-19 vaccines are recommended in children. Vaccine candidates may conduct phase III clinical trials in children to fully assess safety and efficacy before the vaccine is approved for use in these age groups.

  • Can the vaccine be given to people who are immunosuppressed?

    ATAGI recommends COVID-19 vaccination for all immunosuppressed people due to an increased risk of developing severe disease if infected with SARS-CoV-2. Due to limitations in clinical trials there is currently no data on the safety and efficacy of COVID-19 vaccination in this group, however in principle there are no theoretical risks.

    It is anticipated that the immune response to vaccination may be reduced in this patient group depending on the level of immune suppression. Hence, when vaccinating immunocompromised people, they should also be counselled about this reduced efficacy and the need to continue other prevention measures such as social distancing and mask wearing.

    Please speak to your doctor to discuss individual cases and see the following links for more information:

  • What is herd immunity?

    Herd immunity describes when a certain proportion of the community is immune to a specific pathogen (in this case virus). It can only be induced by vaccination; never in history has any virus infection been eliminated because of immunity by natural infection.

    Herd immunity is achieved when more than 60-70% of people in a population are vaccinated against a particular illness. At this level of population immunity, there are fewer people that the pathogen can infect and hence this self-limits the spread of the pathogen.

    Please see more information about herd immunity on the Children’s Hospital of Philadelphia – Questions and Answers about COVID-19 Vaccines.

  • Can COVID-19 vaccines be used to prevent disease in patients who have already been identified as contacts of a COVID-19 positive case?

    COVID-19 vaccine administration is not recommended for post-exposure prophylaxis.

    Please refer to COVID-19 vaccination – ATAGI clinical guidance on COVID-19 Vaccine in Australia in 2021 for more information.

Storage

  • How should COVID-19 vaccines be stored?

    Cold-chain requirements for the newer genetic (DNA and mRNA) vaccines require additional logistical considerations. Comirnaty™ (Pfizer/BioNTech COVID-19 vaccine) vaccine must be stored at –70°C, be transported on dry ice and will only remain stable for 24 hours when refrigerated (2°-8°C). Once reconstituted, the vaccine must be discarded if it has not been used within 6 hours.

    The Moderna vaccine will need long-term storage and transport at –20°C, but once defrosted will remain stable in a standard vaccine fridge (2°-8°C) for 5 days.

    The majority of other vaccine candidates can be stored and managed using standard cold-chain systems (2°-8°C), this includes COVID-19 AstraZeneca vaccine.

  • Are multi-dose vials safe? Why are they being used?

    Multi-dose vials (MDV) are safe as long as each dose is prepared appropriately using aseptic technique. They should be kept and accessed in a dedicated clean medication preparation area and away from immediate patient treatment areas. This is to prevent inadvertent contamination of the vial and cross contamination between patients.

    MDVs are cheaper to produce and occupy less cold-chain capacity. In the context of the COVID-19 pandemic; improved efficiency of production and storage is vital when millions of doses must be produced quickly.

    To learn how to safely prepare and store multi-dose vials please refer to MVEC’s immunisation reference page Multi-dose vials as well as MVEC’s eLearning package on the Use of multi-dose vials accessible via the education portal.

Administration

  • Can COVID-19 vaccines be co-administered with other vaccines?

    Currently, COVID-19 vaccines have not been assessed in clinical trials when co-administered with other vaccines, hence they should be administered alone.

    The Australian Technical Advisory Group on Immunisation (ATAGI) recommends a minimum 14 day interval between administration of a COVID-19 vaccine and other vaccines (including seasonal influenza vaccine).

    For more information please refer to COVID-19 vaccination- ATAGI clinical guidance on COVID-19 vaccine in Australia in 2021.

  • Can COVID-19 vaccines be used interchangeably (eg. using a different vaccine brand for the first and second dose)?

    There is no clinical trial data assessing the interchangeability of different COVID-19 vaccines and hence the same brand of vaccine should be given for both the first and second dose. There is currently no recommendation for further booster doses of COVID-19 vaccines.

    For more information please refer to COVID-19 vaccination- ATAGI clinical guidance on COVID-19 vaccine in Australia in 2021.

  • Can the COVID-19 vaccine be given to people who have previously or currently have COVID-19 disease (or evidence of SARS-CoV-2 infection)?

    Yes, people with previous COVID-19 disease should still be vaccinated to ensure ongoing protection. However, vaccination should be deferred until the person has fully recovered from the acute COVID-19 illness. Clinical trials indicate that it is safe to give COVID-19 vaccines in people with evidence of prior SARS-CoV-2 infection.

  • How many doses will be required? How long will I be protected and do I need a booster dose?

    The recommended schedule for Comirnaty™ (Pfizer/BioNTech COVID-19 vaccine) is two doses given 21 days apart.

    The recommended schedule for COVID-19 AstraZeneca vaccine is two doses given 12 weeks apart (with a minimum interval of 4 weeks apart accepted in certain circumstances).

    Data regarding the length of protection following vaccination is still being gathered from phase III clinical trials. The length of protection is still unclear and hence the timing and need for a booster has not been established. Currently, no additional doses beyond the first two are recommended at this time.

  • What are the ABSOLUTE minimum and maximum intervals for each COVID-19 vaccine dose?

    Vaccination with COVID-19 AstraZeneca vaccine requires a 2-dose course, with ATAGI recommending an interval of 12 weeks between doses. In certain circumstances (eg. impending chemotherapy, amount of circulating disease etc) an absolute minimum interval of 28 days is acceptable. If the second dose is inadvertently administered with an interval of less than 28 days, repeat doses are not currently recommended. If more than 12 weeks has elapsed, the second dose should be administered as soon as possible with no need to re-start the course again. In clinical trials dose 2 was administered at a range of timepoints (4-26 weeks after the first dose) with the greatest efficacy induced when dose 2 was administered 12 weeks after the first dose.

    Vaccination with Comirnaty™ (Pfizer/BioNTech COVID-19 vaccine) requires a 2-dose course administered 21 days apart. The absolute minimum interval is 19 days and the recommended maximum interval is 6 weeks. If the second dose is inadvertently administered with an interval of less than 19 days, repeat doses are not currently recommended. If more than 6 weeks has elapsed, the second dose should be administered as soon as possible with no need to re-start the course again. Clinical trials for Comirnaty™ assessed efficacy when doses were administered at a range of timepoints with these recommendations reflective of the best results obtained.

  • What happens if the second COVID-19 vaccine dose is given early, late or is missed?

    The recommended interval between two doses of Comirnaty™ (Pfizer/BioNTech COVID-19 vaccine) is 21 days, with a minimum interval of 19 days and a maximum interval of 6 weeks. There is currently no recommendation for repeat doses/recommencing the course if there are variations to this advice.

    The recommended interval between two doses of COVID-19 AstraZeneca is 12 weeks, with a minimum interval of 4 weeks apart accepted in certain circumstances. There is currently no recommendation for repeat doses/recommencing the course if there are variations to this advice.

    For more information on dosing recommendations please refer to the following links:

  • How long will it take to develop immunity once vaccinated?

    There is some evidence that one dose of Comirnaty™ (Pfizer/BioNTech COVID-19 vaccine) will provide partial protection after 12 days however this is likely to be short lived. Generally the time required following vaccination for the body to develop immunity will depend on the vaccine; this usually takes a number of weeks. Completing both doses of the 2 dose course is recommended.

  • Are booster doses of COVID-19 vaccines required? Will the current vaccines protect against new strain variants?

    There is currently no recommendation for booster doses of COVID-19 vaccines in Australia. However, due to the limited data on duration of protection and the emergence of SARS-CoV-2 strain mutations, international advisory committees are considering the possibility that doses with updated vaccines will be required in the future.

    To read more refer to the links below:

     

  • I have had a recent blood transfusion; can I have a COVID-19 vaccine?

    Recommendations for delayed vaccination following transfusion with blood products depends on the vaccine and the blood product. As further information becomes available, this answer will be updated.

    Recommendations following blood transfusion generally apply to live-attenuated vaccines, such as MMR (measles-mumps-rubella) or varicella vaccines. There are currently no live-attenuated COVID-19 vaccines planned for use in Australia. The Pfizer/BioNTech vaccine is an mRNA vaccine and the COVID-19 AstraZeneca vaccine is a non-replicating viral vector vaccine.

    In people who have received monoclonal antibodies or convalescent plasma for treatment of COVID-19, the United States’ CDC recommends deferring COVID-19 vaccination for 90 days. This is a precautionary measure to avoid interference of the antibody treatment with vaccine-induced immune responses.

    For more information please refer to the CDC: COVID-19 Vaccine FAQs for Healthcare Professionals and MVEC: Live-attenuated vaccines and immunoglobulins or blood products.

  • I have had a recent live vaccine; can I have a COVID-19 vaccine?

    Due to a lack of safety data on the co-administration of COVID-19 vaccines, ATAGI recommends a 14 day interval between the administration of COVID-19 vaccines and any other vaccine (including live-attenuated vaccines). Please refer to COVID-19 vaccination- ATAGI clinical guidance on COVID-19 vaccine in Australia in 2021 for more information.

  • When administering a COVID-19 vaccine the syringe disconnected from the needle and I am not sure how much of the dose my patient received, what should I do?

    If the process of administering a vaccine is interrupted and most of the dose has not been given, repeat the whole dose as soon as practicable. Please contact your safety service if there are any concerns/questions.

    To read more please refer to the Australian Immunisation Handbook: Administration of vaccines.

  • Can COVID-19 vaccines be given subcutaneously?

    Both COVID-19 AstraZeneca and Comirnaty™ should be administered via intramuscular injection. There is no safety or efficacy data relating to subcutaneous administration.

  • My patient has a history of a bleeding disorder, what is the recommendation regarding intramuscular administration of COVID-19 vaccines?

    COVID-19 vaccines should be administered intramuscularly. Subcutaneous administration is not recommended due to a lack of safety and efficacy data regarding this route of administration.

    There is no absolute contraindication to COVID-19 vaccination in patients who have history of a bleeding disorder, and who have stable INR or anti-Xa levels. However, prior to administration, patients who have bleeding disorders or who are on anti-coagulant therapy, should be advised of the increased risk of bruising, bleeding and haematoma formation. Ensure that the correct needle size and length is used for administration. Firm pressure should be applied to the site (no rubbing) for at least 2 minutes following immunisation.

    For further information please refer to the Australian Immunisation Handbook.

  • Can women with a history of breast cancer receive COVID-19 vaccines?

    Yes. Having a history of breast cancer is not a contraindication for COVID-19 vaccination.

    ATAGI recommends COVID-19 vaccination for all immunosuppressed people (including those undergoing treatment for cancers) due to an increased risk of developing severe disease if infected with SARS-CoV-2. It is anticipated that the immune response to vaccination may be reduced in this patient group depending on the level of immune suppression.

    Lymphadenopathy has been reported as a side effect following vaccination. Given that changes in size and consistency of lymph nodes can also indicate a spread of breast cancer, the Society of Breast Imaging (SBI) has recommended breast screening take place either prior to COVID-19 vaccination or 4-6 weeks following the second dose of COVID-19 vaccines to avoid anxiety and unnecessary examination and diagnostic testing.

    To read more refer to the links below:

     

  • What is the recommended site for injection for patients who have had axillary lymph nodes removed/have a history of lymphoedema?

    There is no strong evidence to suggest that vaccine administration into the deltoid will increase the likelihood of lymphoedema in patients who have had lymph nodes removed or have a previous history of lymphoedema.

    Vaccine administration into the deltoid of the unaffected arm may be preferred, alternatively intramuscular injection into the vastus lateralis (thigh) can be considered.

    To read more refer to the links below:

  • My patient has a history of Guillain Barre Syndrome (GBS), is it safe to administer COVID-19 vaccines?

    Having a history of GBS is not a contraindication to vaccination with COVID-19 vaccines and as such it is safe to administer COVID-19 vaccines in this patient group.

    For more information please refer to MVEC: Guillain-Barre Syndrome page and CDC: Vaccine Considerations for People with Underlying Medical Conditions.

  • Are there any concerns regarding COVID-19 vaccines and Bell’s Palsy?

    People who have previously been diagnosed with Bell’s Palsy can receive COVID-19 vaccines. Cases of Bell’s Palsy following immunisation have been identified in participants in mRNA COVID-19 vaccine candidate clinical trials. However, as the rate of occurrence was not above the background rate expected in the general population, they are not considered to be caused by vaccination.

    For more information refer to CDC: Vaccine Considerations for People with Underlying Medical Conditions.

  • Is it safe for people with a diagnosis of Multiple Sclerosis (MS) to be immunised against COVID-19 vaccines?

    Yes. Whilst there is minimal data on the safety and efficacy of COVID-19 vaccination in people with MS, there are no theoretical concerns relating to administration in this patient group.

    For more information please refer to COVID-19 and vaccination- Everything you need to know.

  • Can patients who are taking monoamine oxidase inhibitors (MAOI’s) be safely immunised with COVID-19 vaccines given that they should generally avoid adrenaline? What would be the appropriate treatment if they experienced anaphylaxis?

    Yes, COVID-19 vaccines should be offered to this patient group.

    True vaccine allergy, or anaphylaxis, is an extremely rare adverse event following immunisation occurring in less than 1 case per million doses administered. Post-licensure surveillance of COVID-19 vaccines show anaphylaxis following administration of COVID-19 AstraZeneca occurring at similar rates to routine vaccines [refer to TGA: AstraZeneca ChAdOx1-S COVID-19 vaccine]. Anaphylaxis following Comirnaty™ (Pfizer/BioNTech), whilst still extremely rare, occurs at a slightly higher rate of approximately 4.7 cases per million doses.

    Patients who take MAOI’s have a theoretical increased risk of developing hypertensive crisis if administered adrenaline (or other specific medications/foods) due to a potential for drug interaction. In the setting of anaphylaxis, resuscitation with adrenaline remains the most appropriate treatment regardless of medical history. The benefits of treating anaphylaxis effectively far outweighs any potential risk of hypertensive crisis.

    Ensuring the diagnosis of anaphylaxis is accurate is an important step to avoid unnecessary administration of adrenaline when not clinically indicated.

    For more information refer to:

Safety

  • How can a COVID-19 vaccine be safe when it was made so quickly?

    COVID-19 vaccine development is happening “faster than usual” because of the global impact of the pandemic and the urgent need for a vaccine(s). Vaccines have traditionally been developed in consecutive sequential stages – with preclinical trials followed by phases I, II and III, often with large gaps of time in-between phases awaiting funding or manufacturing scaleup. With COVID-19, this process has been made more efficient by running one phase while simultaneously also preparing and/or recruiting for the next phase.

    It is important to note that COVID-19 vaccine candidates must pass through the exact same rigor and phases of clinical trials and do not miss any important safety and quality checks or steps. Approval is only given if the vaccine meets the appropriate requirements for safety and efficacy.

    Refer to MVEC: Vaccine development and safety, including “The Road to a COVID-19 Vaccine” animation for more information.

  • How can we be sure that the manufacturing process is safe?

    Like any medication in development, vaccine candidates must undergo rigorous testing procedures and scientific evaluation to prove not only their effect on the targeted disease, but also to determine their safety – before being licensed and registered for use in vaccination programs.

    In all three clinical trial phases, safety is continually assessed as data is gathered and a vaccine must pass all these phases before it can be considered for registration for use by the TGA. By the time a vaccine is registered, safety would have been assessed in tens of thousands of clinical trial participants and this safety data would have been rigorously evaluated by the TGA and other international drug regulatory bodies.

    The quality, sterility, potency and purity of each vaccine batch is also assessed by the TGA prior to being supplied to Australia, as is the quality of selected batches after they have been supplied.

    Once a vaccine is approved, it continues to be tested in a process known as post-licensure surveillance.

  • What are the expected side effects of a COVID-19 vaccine?

    You may experience minor side effects following COVID-19 vaccination. Common side effects include pain, redness and swelling at the injection site as well as more general side effects such as fever, chills, headache and tiredness.

    Most systemic (general) symptoms are mild to moderate in severity, occur within the first three days of vaccination, and resolve within 1–3 days of onset. These symptoms may be more common and severe following the second dose and among younger people compared to older people.

    Serious reactions like allergic reactions are extremely rare. If you have any concerns about the vaccine, ask your doctor, nurse or health care professional.

    For more information, please refer to the following documents:

  • Can a COVID-19 vaccine be given in pregnancy? When breastfeeding?

    The administration of COVID-19 vaccines to pregnant women is not routinely recommended however it is not contraindicated. Currently, there is limited data available on the safety of COVID-19 vaccination in pregnancy and on pregnancy outcomes. ATAGI recommends that immunisation during pregnancy could be considered if there are medical risk factors for developing severe disease or if there is a high risk of exposure to the virus (ie: occupational risk factors). As further data is made available these recommendations may change.

    A recent study published in the American Journal of Obstetrics and Gynecology has evaluated the immunogenicity and reactivity of COVID-19 vaccines administered to a small number of pregnant and lactating women.  Immune responses following immunisation with the Pfizer BioNTech and Moderna COVID-19 mRNA vaccines were  comparable to the responses of non-pregnant counterparts in the study and were far greater than that seen following natural SARS-CoV-2 infection in pregnancy. Maternal immunity was passively transferred to infants via the placenta and breastmilk.

    ATAGI recommends that women who are breastfeeding or who are planning pregnancy can receive COVID-19 vaccines.

    For more information refer to the following:

  • I have received 1 dose of COVID-19 but have now discovered I am pregnant. What does that mean for completing the course?

    The administration of COVID-19 vaccines to pregnant women is not routinely recommended however it is not contraindicated. Currently, there is limited data available on the safety of COVID-19 vaccination in pregnancy and on pregnancy outcomes. Based on what we know about other vaccines it is likely that administering COVID-19 vaccines during pregnancy is safe and effective, however pregnant women were not included in COVID-19 vaccine clinical trials. When considering vaccination during pregnancy a risk/benefit discussion with a health care professional is recommended, to assess medical risk factors for developing severe disease as well as any risk of exposure to the virus (ie: occupational risk factors).

    If the second dose of vaccine is delayed until after the pregnancy it should be noted that there is no need to restart the course again despite the interval between doses being greater than recommended. The level of efficacy may be impacted due to the altered timing of doses. Protective measures such as maintaining social distancing and mask-wearing remain important in reducing the risks of contracting COVID-19.

    For more information refer to the following:

     

     

  • Can a COVID-19 vaccine be given to those with immunosuppression?

    ATAGI recommends COVID-19 vaccination for all immunosuppressed people due to an increased risk of developing severe disease if infected with SARS-CoV-2. Due to limitations in clinical trials there is currently no data on the safety and efficacy of COVID-19 vaccination in this group, however in principle there are no theoretical risks.

    It is anticipated that the immune response to vaccination may be reduced in this patient group depending on the level of immune suppression. Hence, when vaccinating immunocompromised people, they should also be counselled about this reduced efficacy and the need to continue other prevention measures such as social distancing and mask wearing.

    Household contacts of people with immunosuppression are recommended to receive COVID-19 vaccines. This helps protect people who are immunocompromised, whether they are a child or an adult, by reducing their exposure to disease.

    Please speak to your doctor to discuss individual cases and see the following links for more information:

  • How are vaccines monitored for safety post licensure? What is the role of SAEFVIC/TGA?

    Post-licensure safety monitoring in Australia occurs using a variety of mechanisms. These may include:

    Surveillance of Adverse Events Following Vaccination In the Community (SAEFVIC) is the central reporting service in Victoria for any significant AEFI. SAEFVIC collects, analyses and reports data about significant AEFI as part of monitoring vaccine safety in Victoria. All reports are sent to the Therapeutic Goods Administration (TGA) who is responsible for assessing the safety of vaccines and other medicines for use in Australia.

    The role of the TGA is also to determine whether a COVID-19 vaccine candidate meets the strict safety and efficacy requirements for registration before it can be used in Australia.

    For more information refer to the Therapeutic Goods Administration: COVID-19 vaccines.

  • I think I am experiencing some side effects, should I report?

    Any event felt to be significant following immunisation should be reported. You do not need to routinely report common/minor/expected reactions.

    Clinicians must report severe adverse effects through SAEFVIC in Victoria. This should be done whether you think the side effect was related to the vaccine or not.

  • I experienced side effects from the first dose of the vaccine, should I not have the second dose?

    Common side effects that are short lived are not a contraindication to the second dose of COVID-19 vaccine.

    If you have experienced any unanticipated side effects following the first dose COVID-19 vaccine, speak to your healthcare professional about the safety of a second dose.

    If you had an immediate or severe allergic reaction (anaphylaxis) after getting the first dose of a COVID-19 vaccine, you should not get the second dose. Your healthcare provider may refer you an allergy specialist for further advice. Serious reactions like allergic reactions are extremely rare.

  • What is vaccine-associated enhanced disease?

    Vaccine-associated enhanced disease occurs when a more severe presentation of disease develops in an individual who has previously been immunised, compared with when an infection occurs without prior vaccination.

    For more information on VAED please review our reference page MVEC: Vaccine-associated enhanced disease

  • My patient has a history of Guillain Barre Syndrome (GBS), is it safe to administer COVID-19 vaccines?

    Having a history of GBS is not a contraindication to vaccination with COVID-19 vaccines and as such it is safe to administer COVID-19 vaccines in this patient group.

    For more information please refer to MVEC: Guillain-Barre Syndrome page and CDC: Vaccine Considerations for People with Underlying Medical Conditions.

  • Are there any concerns regarding COVID-19 vaccines and Bell’s Palsy?

    People who have previously been diagnosed with Bell’s Palsy can receive COVID-19 vaccines. Cases of Bell’s Palsy following immunisation have been identified in participants in mRNA COVID-19 vaccine candidate clinical trials. However, as the rate of occurrence was not above the background rate expected in the general population, they are not considered to be caused by vaccination.

    For more information refer to CDC: Vaccine Considerations for People with Underlying Medical Conditions.

  • Is it safe for people with a diagnosis of Multiple Sclerosis (MS) to be immunised against COVID-19 vaccines?

    Yes. Whilst there is minimal data on the safety and efficacy of COVID-19 vaccination in people with MS, there are no theoretical concerns relating to administration in this patient group.

    For more information please refer to COVID-19 and vaccination- Everything you need to know.

  • Can patients who are taking monoamine oxidase inhibitors (MAOI’s) be safely immunised with COVID-19 vaccines given that they should generally avoid adrenaline? What would be the appropriate treatment if they experienced anaphylaxis?

    Yes, COVID-19 vaccines should be offered to this patient group.

    True vaccine allergy, or anaphylaxis, is an extremely rare adverse event following immunisation occurring in less than 1 case per million doses administered. Post-licensure surveillance of COVID-19 vaccines show anaphylaxis following administration of COVID-19 AstraZeneca occurring at similar rates to routine vaccines [refer to TGA: AstraZeneca ChAdOx1-S COVID-19 vaccine]. Anaphylaxis following Comirnaty™ (Pfizer/BioNTech), whilst still extremely rare, occurs at a slightly higher rate of approximately 4.7 cases per million doses.

    Patients who take MAOI’s have a theoretical increased risk of developing hypertensive crisis if administered adrenaline (or other specific medications/foods) due to a potential for drug interaction. In the setting of anaphylaxis, resuscitation with adrenaline remains the most appropriate treatment regardless of medical history. The benefits of treating anaphylaxis effectively far outweighs any potential risk of hypertensive crisis.

    Ensuring the diagnosis of anaphylaxis is accurate is an important step to avoid unnecessary administration of adrenaline when not clinically indicated.

    For more information refer to:

Allergies

  • Is it safe to administer COVID-19 vaccines to people with latex allergies?

    The COVID-19 vaccines with provisional registration for use within Australia (Comirnaty™ and COVID-19 AstraZeneca) can both be administered to people with latex allergies following standard precautions, with a 15 minute post-vaccination observation period. Neither Comirnaty™ or COVID-19 AstraZeneca vials contain latex.

    For more information please refer to the ASCIA: Allergy, Immunodeficiency, Autoimmunity and COVID-19 Vaccination Position Statement.

  • My patient has a history of allergies, is it safe to administer a COVID-19 vaccine to them?

    The only two absolute contraindications to vaccination are anaphylaxis to a previous dose of the same vaccine or anaphylaxis to a component of the vaccine. For specific advice please contact your specialist immunisation service.

    For patients with a history of anaphylaxis to food, drugs, venom or latex, it is recommended a routine observation period of 15 minutes following COVID-19 vaccination is observed.

    Additional precautions are recommended for individuals with possible allergic reactions to a previous dose of a COVID-19 vaccine; allergic reactions to ingredients in the COVID-19 vaccine to be administered (including PEG in Comirnaty™ and Polysorbate 80 in COVID-19 AstraZeneca); prior anaphylactic reactions to other vaccines or medications where PEG or Polysorbate 80 may have been the cause; or a known systemic mast cell activation disorder with raised mast cell tryptase that has required treatment.

    In these instances a specialist review by an immunology/allergy/vaccination specialist to undertake a risk/benefit assessment to assess suitability for vaccination should be undertaken.

    Pleaser refer to COVID-19 vaccination – ATAGI clinical guidance on COVID-19 Vaccine in Australia in 2021 or the ASCIA: Allergy, Immunodeficiency, Autoimmunity and COVID-19 Vaccination Position Statement for more information.

  • My patient has a history of allergy to Polyethylene Glycol (PEG), can I administer a COVID-19 vaccine to them?

    PEG is an ingredient contained in Comirnaty™. It is also a commonly used ingredient of other medications, hand sanitisers, cosmetics, bathroom products and colonoscopy preparation products, routinely used within Australia. Whilst it is uncertain whether PEG contained in mRNA vaccines may trigger anaphylaxis, additional precautions are required.

    If your patient has a history of confirmed or suspected allergy to PEG it is recommended that they are referred to an immunology/allergy/vaccination specialist for advice regarding the safety of administering an mRNA COVID-19 vaccine.

    NB: Vaccination with the Comirnaty™ COVID-19 vaccine is contraindicated in people with documented anaphylaxis to PEG.

    To read more refer to COVID-19 vaccination – ATAGI clinical guidance on COVID-19 Vaccine in Australia in 2021.

  • My patient has a history of allergy to Polysorbate 80, can I administer a COVID-19 vaccine to them?

    Polysorbate 80 is chemically related to Polyethylene Glycol (see question above) and is an ingredient in COVID-19 AstraZeneca.

    If your patient has a history of confirmed or suspected allergy to Polysorbate 80 it is recommended that they are referred to an immunology/allergy/vaccination specialist for advice regarding the safety of administering COVID-19 AstraZeneca.

    NB: Vaccination with the COVID-19 AstraZeneca is contraindicated in people with documented anaphylaxis to Polysorbate 80.

    For further information please refer to ASCIA: Allergy, Immunodeficiency, Autoimmunity and COVID-19 Vaccination Position Statement and COVID-19 vaccination – ATAGI clinical guidance on COVID-19 Vaccine in Australia in 2021.

  • Do COVID-19 vaccines contain gelatin?

    Both COVID-19 AstraZeneca and Comirnaty™ are gelatin free and safe to administer to patients who are allergic to gelatin. A standard 15-minute observation period following immunisation is recommended.

  • What are the ingredients of COVID-19 vaccines?

    There are currently 2 COVID-19 vaccine with provisional registration in use in Australia.

    Each dose of Comirnaty™ (Pfizer/ BioNTech COVID-19 vaccine) contains:

    • 30 mcg mRNA encoding the SARS-CoV-2 spike glycoprotein
    • (4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2- hexyldecanoate) (ALC-0315)
    • 2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide (ALC0159)
    • Distearoylphosphatidylcholine (DSPC)
    • Cholesterol
    • Potassium chloride
    • Monobasic potassium phosphate
    • Sodium chloride
    • Dibasic sodium phosphate dihydrate
    • Sucrose
    • Water for injections

    Each dose of COVID-19 AstraZeneca (Oxford/AstraZeneca COVID-19 vaccine) contains:

    • 5×1010 viral particles of ChAdOx1-S
    • Histidine
    • Histidine hydrochloride monohydrate
    • Sodium chloride
    • Magnesium chloride hexahydrate
    • Disodium edetate (EDTA)
    • Sucrose
    • Ethanol absolute
    • Polysorbate 80
    • Water for injection

    Further information can be found in the Product Information for each vaccine:

  • Is there an increased risk of anaphylaxis following COVID-19 vaccines?

    A true vaccine allergy (anaphylaxis), where a person is contraindicated from being immunised with the same vaccine in the future, is rare (in most studies reported as less than 1 case per million doses).

    Post-licensure surveillance of COVID-19 vaccines show anaphylaxis following administration of COVID-19 AstraZeneca occurring at similar rates to routine vaccines. Anaphylaxis following Comirnaty™, while still extremely rare, occurs at a slightly higher rate of approximately 4.7 cases per million doses.

    To read more follow the links below:

     

COVID-19 Astra-Zeneca

  • Are people > 50 years of age receiving an “inferior” vaccine?

    Both Comirnaty™ and COVID-19 AstraZeneca are effective vaccines which protect against severe COVID-19 disease and hospitalisation.

    The recommendation by ATAGI does not mean or indicate that there are questions over the effectiveness of the vaccine in any age group.

  • I am under 50 years of age and have had dose 1 of the AstraZeneca vaccine, is it safe to receive dose 2?

    People who have received their first dose of COVID-19 AstraZeneca without any serious adverse events can receive their second dose. This should be done in the recommended time frame of 4-12 weeks between doses. Current information suggests that thrombosis with thrombocytopenia syndrome is more frequently reported following receipt of dose 1 of COVID-19 AstraZeneca.

    For more information refer to ATAGI statement on AstraZeneca vaccine in response to new vaccine safety concerns.

  • I am under 50 years of age and received COVID-19 AstraZeneca as my first dose, should I/can I have Comirnaty™ as my dose 2 of a COVID-19 vaccine? Or now commence a course of 2 doses of Comirnaty™ and no further doses of AstraZeneca?

    There is no data on the safety and efficacy of using alternate brands to complete a course of COVID-19 vaccination. Current information suggests that thrombosis with thrombocytopenia syndrome (TTS) is more frequently reported following receipt of dose 1 of COVID-19 AstraZeneca. If a person has received the first dose of COVID-19 AstraZeneca without any serious adverse events such as TTS or anaphylaxis, then they can receive the second dose.

    COVID-19 vaccination is not mandatory, however immunisation is strongly recommended for all who are eligible to receive it. It is important to discuss any queries or concerns with an immunisation provider or your treating health care professional.

  • I am over 50 years of age and have a history of deep vein thrombosis (DVT’s). Is it safe for me to receive COVID-19 AstraZeneca?

    The international vaccine regulators such as the EMA, MHRA and TGA have been conducting investigations into the reports of blood clotting conditions following COVID-19 AstraZeneca. There is currently no evidence to suggest that having a history of DVT’s or other general thromboembolic disorders predisposes you to developing TTS following administration of COVID-19 AstraZeneca.

    In contrast, there is strong evidence that COVID-19 disease is thrombogenic (promotes clot development) and may cause a variety of thromboembolic events.

    Refer to Updated ATAGI statement for healthcare providers on a specific clotting condition being reported after COVID-19 vaccination for more information.

  • I am under 50 years of age and travelling to an area experiencing a current COVID-19 outbreak. Should I have the AstraZeneca vaccine as I am unable to source an alternative?

    ATAGI recommends that COVID-19 AstraZeneca can be administered in adults aged under 50 years of age where the benefits of protection are likely to outweigh the risks of vaccination for that individual. It is important to discuss your individual circumstances with a health care provider in order to make an informed decision. There may be some differences to this advice depending on the state/jurisdiction you live in, so please check with your local Department of Health.

    To read more refer to ATAGI statement on AstraZeneca vaccine in response to new vaccine safety concerns.

  • I am under 50 years of age and allergic to Polyethylene Glycol (PEG) which is an ingredient of Comirnaty™. Can I/should I receive COVID-19 AstraZeneca?

    PEG is an ingredient contained in Comirnaty™ and it is therefore recommended that you are referred to an immunology/allergy/vaccination specialist for advice regarding the safety of receiving the Pfizer/BioNTech vaccine.

    Whilst ATAGI advises that Comirnaty™ is the preferred COVID-19 vaccine for those aged under 50 years, it can be administered in this age group where the benefits of protection are likely to outweigh the risks of vaccination for that individual. It is important to discuss your individual circumstances with a health care provider in order to make an informed decision.

    NB: Vaccination with Comirnaty™ is contraindicated in people with documented anaphylaxis to PEG.

    For more information refer to COVID-19 vaccination – ATAGI clinical guidance on COVID-19 vaccine in Australia in 2021

  • I am over 50 years of age and allergic to Polysorbate 80, an ingredient of COVID-19 AstraZeneca. Will I be able to have Comirnaty™?

    Polysorbate 80 is an ingredient contained in COVID-19 AstraZeneca and it is therefore recommended that you are referred to an immunology/allergy/vaccination specialist for advice regarding the safety of receiving the vaccine or whether an alternate brand (currently Comirnaty™) is preferred.

    NB: Vaccination with the COVID-19 AstraZeneca is contraindicated in people with documented anaphylaxis to Polysorbate 80.

    For more information refer to COVID-19 vaccination – ATAGI clinical guidance on COVID-19 vaccine in Australia in 2021

  • I am taking hormone replacement therapy. Am I at an increased risk of thrombosis with thrombocytopenia syndrome (TTS) if I am given COVID-19 AstraZeneca?

    There is currently no evidence to suggest that taking certain medications or being prone to developing blood clots puts you at increased risk of developing TTS following receipt of COVID-19 AstraZeneca.

  • I am over 50 years of age and have a history of atrial fibrillation putting me at a higher risk of blood clots. Is it safe for me to have COVID-19 AstraZeneca?

    There is currently no evidence to suggest that having a medical condition which increases your likelihood of developing blood clots puts you at a greater risk of developing TTS following receipt of COVID-19 AstraZeneca.

  • I am under 50 years of age and I just want to be vaccinated ASAP. Can I have COVID-19 AstraZeneca as it is more readily available?

    Whilst ATAGI preferentially recommends administration of an alternate brand of COVID-19 vaccine (Comirnaty™) in those aged under 50 years, it is not contraindicated. It is important to be informed of common, expected and rarer side effects of vaccination prior to receiving any vaccine. The risk of developing thrombosis with thrombocytopenia syndrome (TTS) following receipt of COVID-19 AstraZeneca is rare with current evidence suggesting a rate of approximately 4-6 cases per 1 million doses of the vaccine administered.

  • What is thrombosis with thrombocytopenia syndrome (TTS)?

    Thrombosis with thrombocytopenia syndrome (TTS), is a rare and new syndrome which has been reported in people who have received COVID-19 AstraZeneca vaccination.

    The estimated risk of developing TTS is approximately 4 to 6 persons per million doses following dose 1 of COVID-19 AstraZeneca. Current information suggests that TTS is more frequently reported following receipt of dose 1 of COVID-19 AstraZeneca.

    The features of TTS are usually seen in days 4-20 after vaccination. They may include symptoms of blood clots in various organs including (but not limited to):

    • Neurological
      • Severe headaches unresponsive to simple analgesia
      • Visual changes (eg. blurred vision)
      • Focal neurological deficits/changes
      • Confusion/encephalopathy
      • Seizures
    • Gastroenterology
      • Abdominal pain
      • Vomitting
    • Respiratory
      • Significant respiratory symptoms/distress

    There is currently no exact mechanism identified to describe how COVID-19 AstraZeneca may trigger TTS. There is some indication that this is an immune-mediated process, with some recent publications using the title vaccine induced immune prothrombotic immune thrombocytopenia (VIPIT), but we will use the term TTS in these MVEC FAQs.

  • Are there any risk factors for developing thrombosis with thrombocytopenia syndrome (TTS)? eg. age, gender etc

    Evidence thus far indicates there is a higher risk of thrombosis with thrombocytopenia syndrome (TTS) in the younger population (< 50 years of age), although there has been a small number of cases identified in older adults. There is some evidence to suggest that the incidence is higher in women compared to men, although this may be because more vaccine doses have been administered to women in vaccine rollouts worldwide, especially those targeting healthcare professionals.

    TTS is an idiosyncratic reaction. There are currently no biological risk factors that have been identified to either increase or decrease your risk of TTS. This includes a past history of clots in the leg (DVT), lungs (pulmonary embolus [PE]) or heart (myocardial infarction).

  • When do symptoms of thrombosis with thrombocytopenia syndrome (TTS) following COVID-19 AstraZeneca occur?

    Symptoms of TTS have been reported to occur in the 4-20 day time period following administration of COVID-19 AstraZeneca. Current information suggests that TTS is more frequently reported following receipt of dose 1 of COVID-19 AstraZeneca.

    The features of TTS may include symptoms of blood clots in various organs including (but not limited to):

    • Severe headaches unresponsive to simple analgesia
    • Abdominal pain
    • Significant respiratory symptoms/distress
    • Visual changes
    • Vomiting
    • Seizures
    • Focal neurological deficits/changes
    • Confusion/encephalopathy

  • I am 51 years of age. Why is COVID-19 AstraZeneca deemed safe for me to receive?

    Like any arbitrary age cut-off, it is acknowledged that there may be limited difference between an individual at age 50 or 51 years. What we do know is that the risk of intensive care admissions and death increases markedly with age, with each decade of life increasing the risk 3-fold. Conversely, the possibility of thrombosis with thrombocytopenia syndrome (TTS) may be higher in younger people, based on currently available data.

    ATAGI have taken this data, along with safety data analysis from other countries such as the UK, other risks such as prevalence of COVID-19 in the Australian population along with any existing COVID-19 outbreaks, to calculate an age-specific benefit-to-risk balance for the Australian population. This has resulted in a current age cutoff of 50 years old in the current recommendations.

  • What is the risk-benefit ratio (also known as benefit-risk-assessment) when weighing up whether to get vaccinated?

    A benefit-risk assessment is important to conduct when recommending any vaccination. This measures the benefits of vaccination (eg. reduction of morbidity and mortality from the disease) to any potential risks. Also known as a benefit-risk ratio or balance, it will vary with other factors such as age, prevalence of outbreaks in a population and potential exposure to the disease in their workplace. This assessment may differ from individual to individual.

    For COVID-19, older people are at an increased risk of severe disease and death if they contract COVID-19. Younger people with some underlying medical conditions are also at an increased risk of severe disease, which affects their benefit-to-risk balance.

    The absence of COVID-19 in the community also affects this benefit-to-risk balance. Current advice would be reconsidered in the context of an outbreak, as the benefit in preventing COVID-19 would outweigh the risk for most adults.

    For more information on weighing up the potential benefits vs risk of harm please refer to Weighing up the potential benefits against risk of harm from COVID-19 AstraZeneca.

    Whilst the current recommendations in Australia are that Comirnaty™ (Pfizer) COVID-19 vaccine is preferred in people under 50, a person in this age group can make an informed decision in conjunction with their healthcare provider to receive a COVID-19 AstraZeneca vaccine based on an understanding of their individual benefit-risk assessment.

  • Can I get a blood test to check my immune response from the first dose and avoid the need for a second dose?

    COVID-19 serology is not routinely available following vaccination and is not able to inform the decision to proceed with a second dose. Due to the novel nature of SARS-CoV-2, a correlate of protection has not yet been established for COVID-19 in humans.

    Data from clinical trials demonstrated that a 12-week interval between doses of COVID-19 AstraZeneca provided a significant increase in the immune response and longer-term protection. COVID-19 AstraZeneca is provisionally licensed by the Therapeutic Goods Administration as a two dose schedule.

    Refer to COVID-19 vaccination- ATAGI clinical guidance on COVID-19 vaccine in Australia in 2021 for more information.

  • How much protection do I get from 1 dose of COVID-19 AstraZeneca?

    The level of protection gained from a single dose of COVID-19 AstraZeneca was assessed during clinical trials in an exploratory analysis that included participants who had received one dose. Protection was 73%, with the 95% CI from 49% and 86%, starting from 3 weeks after the first dose. This analysis reflects the short term efficacy and does not demonstrate the duration of protection. It is important to note that COVID-19 AstraZeneca is provisionally licensed by the Therapeutic Goods Administration as a two dose schedule.

    Refer to COVID-19 vaccination- ATAGI clinical guidance on COVID-19 vaccine in Australia in 2021 or COVID-19 AstraZeneca Product Information for more information.

  • I’m unsure about having COVID-19 AstraZeneca, can I wait for an alternate vaccine brand?

    Then is no certainty regarding when additional alternate vaccine brands will be available in Australia.

    Whilst the Australian government have announced that an additional 20 million doses of Comirnaty™ have been secured, these will not be available until later in 2021.

    There is an advance purchase agreement for the Novavax vaccine candidate which is still in phase III trials. Once trials have been completed, if proven safe and effective, this vaccine would still need to obtain provisional registration prior to any rollout in Australian. Doses of Novavax vaccine will be manufactured overseas and as such availability will be depend on the ability to import doses.

    In making this decision it is important to be aware of the potential for a COVID-19 outbreak. While Australia currently has minimal community transmission of COVID-19, this could change. Factors to consider include winter months approaching, high rates of global transmission, the emergence of new variants of the virus, as well as the potential for future changes to Australia’s border controls.

  • ATAGI have noted that “people who have had their first dose of COVID-19 AstraZeneca without any serious adverse effects can be given a second dose, including those under 50 years”. What constitutes a serious adverse event?

    A serious adverse event following immunisation (AEFI) includes anaphylaxis or thrombosis with thrombocytopenia syndrome (TTS).

    Anaphylaxis to a previous dose of a vaccine is a contraindication to future doses of that same vaccine. Those with a past history of TTS or central venous sinus thrombosis (CVST) are advised not to receive COVID-19 AstraZeneca.

    Specialist immunisation advice can be sought by referring patients to the VicSIS network if further clarification is required. VicSIS has been established to provide specialist immunisation support for those who have experienced AEFI or those who are identified at risk of AEFI.

  • I am over 50 years of age and my GP has recommended that I be immunised with Comirnaty™. What happens now?

    There are a limited range of indications for a person aged 50 years of age and older to require Comirnaty™ rather than COVID-19 AstraZeneca.

    These include:

    • Anaphylaxis after a previous dose of COVID-19 AstraZeneca
    • Anaphylaxis to polysorbate 80 (a component of COVID-19 AstraZeneca)

    At this time, given the reported association of COVID-19 AstraZeneca with a very rare but serious clotting disorder (thrombosis) together with low platelet count (thrombocytopenia), it is also advised that Comirnaty™ (rather than COVID-19 AstraZeneca) be used in people with a past history of:

    • Past history of heparin induced thrombocytopenia (HITS)
    • Past history of central venous sinus thrombosis (CVST)

    If a doctor feels their patient aged 50 years or older has a medical contraindication to receiving COVID-19 AstraZeneca and should be offered Comirnaty™ instead, the doctor can make a referral of their patient to the VicSIS network for management.

Authors: Daniela Say (MVEC Immunisation Fellow), Georgina Lewis (SAEFVIC Clinical Manager, Murdoch Children’s Research Institute), Rachael McGuire (MVEC Education Nurse Coordinator) and Francesca Machingaifa (MVEC Education Nurse Coordinator)

Reviewed by: Rachael McGuire (MVEC Education Nurse Coordinator) and Francesca Machingaifa (MVEC Education Nurse Coordinator)

Date: April 25, 2021

Materials in this section are updated as new information and vaccines become available. The Melbourne Vaccine Education Centre (MVEC) staff regularly reviews materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family’s personal health. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult a healthcare professional.


COVAX Facility

The Australian Government has joined the COVAX Facility as part of a global effort to support fair and equitable access to COVID-19 vaccines. This participation and investment means that Australia is able to purchase vaccine doses as they become available from a diverse portfolio of potential COVID-19 vaccines.

The Australian government has invested $123.2 billion to allow the purchase of 25 million doses of COVID-19 vaccines for the Australian population. Australia has committed a further $80 million to support vaccines for 94 lower-income countries. The Department of Foreign Affairs and Trading (DFAT) also announced a $500 million commitment over 3-years to support COVID19 vaccination in Pacific Islander Countries (SICs) and South-east Asia via the Regional Vaccine Access and Health Security Initiative.

Background

COVAX is coordinated by Gavi (the Vaccine Alliance), the Coalition for Epidemic Preparedness Innovations (CEPI) and the World Health Organization. It brings together governments of over 180 countries, global health organisations, private sector, scientists and manufacturers, in order to provide innovative and equitable access to COVID-19 diagnostics, treatments and vaccines.

COVAX pools funding to support research, development and manufacturing of a wide range of COVID-19 vaccine candidates. All participating countries, regardless of income levels, will have equitable access to these vaccines once they are developed.

COVAX has the world’s largest and most diverse portfolio of COVID-19 vaccines. The initial aim is to have 2 billion doses available by the end of 2021, which should be enough to protect high risk and vulnerable people, as well as frontline healthcare workers.

The COVAX portfolio includes:

Vaccine name Vaccine platform Current stage of clinical trials
University of Oxford/AstraZeneca Viral vector Phase 3
Novavax, USA Protein (nanoparticle) Phase 3
Moderna, USA mRNA Phase 3
CureVac, Germany mRNA Phase 2B/3
Inovio, USA DNA Phase 2
Institut Pasteur/Merck/Themis, France/USA/Austria Viral vector Phase 1
Clover Biopharmaceuticals Protein Phase 1
SK bioscience, South Korea Protein (nanoparticle) Preclinical
University of Hong Kong Viral vector Preclinical

Additional agreements have been made with:

  • Johnson & Johnson/Janssen for 500 million doses of their vaccine candidate, via a memorandum of understanding
  • Sanofi/GSK for 200 million doses of their vaccine candidate, via a statement of intent between Gavi, Sanofi and GSK

Resources

Authors: Daniela Say (MVEC Immunisation Fellow) and Nigel Crawford (Director SAEFVIC, Murdoch Children’s Research Institute) 

Date: January 2021

Materials in this section are updated as new information and vaccines become available. The Melbourne Vaccine Education Centre (MVEC) staff regularly reviews materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family’s personal health. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult a healthcare professional.