Australian Academy of Science- The Science of Immunisation: Questions and Answers
The Australian Academy of Science have released an updated edition of The Science of Immunisation- Questions and Answers. This resource has been developed to assist in the understanding of the scientific processes behind vaccination and to encourage trust in vaccines for COVID-19 and other diseases.
Topics include:
- What is immunisation?
- What is in a vaccine?
- Who benefits from vaccines?
- Are vaccines safe?
- What does the future hold for vaccination?
You can view this resource online via the following link:
Australian Academy of Science- The Science of Immunisation: Questions and Answers
Provisional determination granted to Pfizer in relation to COVID 19 vaccine, COMIRNATY - for use in individuals 12 years of age and older
The Therapeutic Goods Administration (TGA) has granted provisional determination to Pfizer's COVID-19 vaccine, Comirnaty™ as part of an application process to lower the approved age limit of vaccine administration from 16 years and above, to individuals aged 12 years and above.
Provisional determination is the first step in the provisional registration pathway. The provisional pathway for registration provides a formal and transparent mechanism for speeding up the registration of promising new medicines based on preliminary clinical data. Having provisional determination does not mean that provisional registration will be granted.
To read more follow the link below:
NEJM: Effectiveness of the BNT162b2 Covid-19 Vaccine against the B.1.1.7 and B.1.351 Variants
The following article, published in the NEJM, assessed the vaccine efficacy of Comirnaty™ (BNT162b2) in Qatar where the predominant circulating strains of SARS-CoV-2 were the UK and South African variants.
By extracting information from the national COVID-19 databases, vaccine effectiveness against the B.1.1.7 (UK) strain was estimated at 89.5%, and 75.0% against the B.1.351 (South African) strain. Vaccine effectiveness against severe disease caused by infection with either variant strain was 97.4%.
For more information on these results refer to the link below:
NEJM: Effectiveness of the BNT162b2 Covid-19 Vaccine against the B.1.1.7 and B.1.351 Variants
Australia secures Moderna vaccines
The Australian Government has secured the supply of 25 million doses of the Moderna COVID-19 vaccine. This agreement will allow access to the current Moderna vaccine formulation (10 million doses) as well as variant-specific versions of the vaccine (15 million doses) in order to address the need for long term immunity and emerging SARS-CoV-2 variants.
Clinical trial results have demonstrated that the Moderna vaccine has 100% efficacy against severe COVID-19 disease, as well as a longer term efficacy of of 90% at least 6 months after the 2nd dose. Supply of the vaccine to Australia will begin only if approval has been provided by the Therapeutic Goods Administration (TGA).
Discussions with Moderna are also underway regarding the establishment of manufacturing facilities within Australia to ensure continued vaccine supply.
To read more follow the link below:
Australia secures Moderna vaccines
NEJM: Efficacy of NVX-CoV2373 Covid-19 Vaccine against the B.1.351 Variant
Novavax have published preliminary phase 2a-b clinical trial results for their COVID-19 vaccine candidate (NVX-CoV2373), assessing vaccine efficacy against SARS-CoV-2 variants (B.1.351- South African strain). This vaccine candidate is a nanoparticle based vaccine containing pieces of the SARS-CoV-2 spike protein.
In this study, participants aged between 18 and 84 years, received either a 2 dose course of the candidate vaccine or a 2 dose course of a placebo (normal saline). Approximately 30% of participants were seropositive for SARS-CoV-2 prior to commencing the trial. Among the seronegative participants, approximately 94% were HIV-negative and 6% were HIV-positive.
A vaccine efficacy of 49.4% was seen among participants who were seronegative at baseline, regardless of HIV status. In the HIV-negative cohort, vaccine efficacy was 60.1%. A history of previous SARS-CoV-2 infection did not reduce the risk of subsequent infection with the new variants of SARS-CoV-2.
To read the article and view these results in full please refer to the below link:
NEJM: Efficacy of NVX-CoV2373 Covid-19 Vaccine against the B.1.351 Variant
Guidance for differentiating anaphylaxis from acute stress response for vaccine providers and Emergency Departments
Anaphylaxis following immunisation is extremely rare but can be life-threatening if not managed effectively. There are many conditions with similar presentations to anaphylaxis without being true anaphylaxis (eg. vasovagal, anxiety, vocal cord dysfunction) which can make the diagnosis difficult.
The Department of Health and the VicSIS network have put together Guidance for differentiating anaphylaxis from acute stress response for vaccine providers and Emergency Departments. This helpful resource provides a comparison of signs and symproms, as well as highlights the importance of measuring tryptase levels in patients with suspected anaphylaxis.
This guidance can be found in the resources section of the below reference page:
MVEC: COVID-19 vaccines and allergy
New immunisation reference page: COVID-19 vaccines in people with immunocompromise
Despite vaccination being recommended, there is currently minimal data on the safety and efficacy of COVID-19 vaccines in the immunocompromised population. In principle, there are no theoretical safety risks and no vaccine safety signals have been identified for vaccinated people with immunocompromise to date. Similar to responses following the administration of other inactivated vaccines in immunocompromised people, a reduced efficacy may occur following vaccination against COVID-19.
Our new reference page collates the various recommendations and guidance available for a broad group of immunocompromising conditions and therapies, as well as providing specific recommendations and/or links where available.
To read more, follow the link below:
MVEC: COVID-19 vaccines in people with immunocompromise
NEJM: Preliminary Findings of mRNA Covid-19 Vaccine Safety in Pregnant Persons
Whilst there is currently limited safety data on the use of COVID-19 vaccines in pregnancy, immunisation in this patient group is not contraindicated. ATAGI advises that COVID-19 immunisation may be recommended after considering factors such exposure risk and underlying medical conditions.
The following study involving 35,691 pregnant participants who received mRNA COVID-19 vaccines did not show any safety signals regarding pregnancy or neonatal outcomes. Preliminary results showed that injection site pain was reported more commonly amongst pregnant women than non-pregnant women, and headache, myalgia, chills and fever were reported less commonly.
To read more, follow the link below:
NEJM: Preliminary Findings of mRNA Covid-19 Vaccine Safety in Pregnant Persons
ATAGI reinforce recommendations on use of COVID-19 vaccines following review of vaccine safety data and benefits
As of April 23, 2021 a total of 6 cases of thrombosis with thrombocytopenia syndrome have been reported in Australia in people who have received dose 1 of COVID-19 AstraZeneca. Severity of cases have varied including 1 fatal outcome. In all reported cases, symptoms of TTS began 4-26 days after immunisation.
The latest statement from ATAGI reinforces the current advice:
- Comirnaty™ is the prefered COVID-19 vaccine brand for administration in those < 50 years of age. COVID-19 AstraZeneca may be administered in this age group if the benefits of immunisation are deemed to outweigh any risks
- Due to the ongoing potential for a COVID-19 outbreak, as well as an increased risk of severe disease and mortality associated with COVID-19 infection, the benefit of immunisation with COVID-19 AstraZeneca for adults > 50 years of age continues to outweigh the risks associated with the vaccine
- TTS can occur at any age, however current evidence shows that the incidence of TTS is less for older adults than younger adults
- ATAGI continues to recommend that people who received the first dose of COVID-19 AstraZeneca without any serious adverse event (eg. anaphylaxis or TTS) can receive the second dose. Current data suggests that the risk of TTS following receipt of a second dose of COVID-19 AstraZeneca is considerably lower. From more than 2 million second doses administered internationally, there has been 1 case of TTS reported following dose 2 of COVID-19 AstraZeneca (reported in the UK)
To read the statement in full refer to the link below:
Reuters: Canada’s Ontario to expand use of AstraZeneca COVID vaccine as epidemic rages
As a third wave of COVID-19 infections spreads across Canada, a change in recommendation for the COVID-19 vaccine rollout has been announced for Ontario. People who will turn 40 years of age this year can now be offered the AstraZeneca COVID-19 vaccine.
Last month, Health Canada (the medicines regulatory board) advised that administration of the AstraZeneca COVID-19 vaccine be limited to those over 55 years of age. This age limit was put in place following reports globally of serious blood clots and bleeding in people who had received COVID-19 AstraZeneca.
With 4,250 new cases of COVID-19 infection diagnosed in Ontario on Sunday and a total of 737 patients requiring intensive care, the benefits of immunising a younger age group is now deemed to outweigh any risk of side effects.
It is recommended that following immunisation, anyone who experiences shortness of breath, chest pain, leg swelling, persistent abdominal pain, neurological symptoms like severe headaches or blurred vision, or skin bruising or tiny blood spots under the skin beyond the site of the injection seek medical attention.
To read more about the change in recommendation refer to the below link:
Reuters: Canada’s Ontario to expand use of AstraZeneca COVID vaccine as epidemic rages