Development of vaccines

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 Australia, the Therapeutic Goods Administration (TGA) is responsible for assessing vaccines and other medicines for use in Australia.

Once vaccines have been introduced into the community, the safety and effectiveness of vaccines then continues to be monitored in the post-licensure phase through active surveillance programs and further trials. This is to ensure that there are no issues that may have been missed during the development phase.

Development phase

During vaccine development, initial safety testing of a vaccine candidate occurs in two stages. Stage one involves preclinical assessment in the laboratory.  Stage two involves the evaluation of the vaccine candidate in three phases of clinical trials. If a vaccine candidate fails the safety tests performed in stage one, it cannot progress further into the stage two clinical trials.

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 people to determine: how effectively it stimulates immune responses; to determine the optimal dose regimen; and whether there are any side effects.

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

A vaccine must pass all of these phases before it is registered for use by the TGA. Approval of vaccines can take up to 10 years.

Post-licensure phase

Despite the extensive safety testing undertaken before a vaccine is licensed, some side effects are so uncommon, they cannot be detected even after studying a vaccine in thousands of people. For this reason, post-licensure assessment is performed.

Safety and effectiveness continue to be monitored using a variety of mechanisms. These may include:

  • further clinical trials
  • surveillance of the impact of the vaccine on the disease it aims to prevent using networks such as PAEDS
  • surveillance of adverse events following immunisation using systems such as AusVaxSafety and reporting services like SAFEVAC and SAEFVIC

What happens if a problem is suspected?

Any suspected problem with a vaccine signals the need for a thorough investigation by the TGA.

If a suspected problem could be serious, authorities will consider a range of actions including suspending use of the vaccine during the investigation.

COVID-19 vaccine development process

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). It is important to note that a candidate COVID-19 vaccine(s) must pass through the same phases of clinical trials and hasn't missed any of the important steps. Approval will only be given if the vaccine meets the requirements for safety and efficacy.

Provisional registration can be granted using a formal pathway for speeding up the registration of a COVID-19 vaccine candidate using preliminary clinical data. The decision to grant provisional registration is based on a number of factors, and ensures that the safety, quality and effectiveness of the vaccine has been satisfactorily established for its intended use. Following provisional approval, the Therapeutic Goods Administration (TGA) will continue to closely monitor any new data about the vaccine as it becomes available [refer to MVEC: Provisional registration of COVID-19 vaccine(s) in Australia].

 

Resources

Authors: Georgina Lewis (Clinical Manager SAEFVIC, Murdoch Children's Research Institute) and Rachael McGuire (SAEFVIC Research Nurse, Murdoch Children's Research Institute)

Reviewed by: Georgina Lewis (Clinical Manager SAEFVIC, Murdoch Children's Research Institute) and Rachael McGuire (SAEFVIC Research Nurse, Murdoch Children's Research Institute)

Date: December 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.


Drive-through immunisation clinics

Drive-through immunisation clinics are an alternative venue for supporting vaccine delivery. A drive-through clinic can assist members of the community to continue to receive recommended immunisations whilst maintaining physical distancing.

A drive-through clinic may not be a setting that is recommended for all patients. It is important that patients be screened for their suitability to use a drive-through service prior to immunisation. Pre-screening of patients can identify previous immunisation reactions, history of vasovagal reactions or needle phobia.

Running sessions by appointment may allow for planning the type and amount of vaccines required and also allows the flow of patients to be staggered in order to prevent traffic congestion.

Preparation for drive-through clinics

There are many different factors that need to be considered when setting up for this type of immunisation venue.

The location:

Consider a location within close proximity of the GP service or health care facility (if applicable). An ideal location would allow for a 1-directional flow of traffic in order to avoid congestion and ensure the safety of roaming staff members. Each individual parking bay should allow enough room for all 4 car doors to completely open without any obstructions (to ensure full access to each patient should AEFI occur).

Equipment:

Carefully consider the equipment required to set up and maintain a drive-through clinic. Equipment should include clear signage, bed/chair to manage adverse events if required, an anaphylaxis response kit, essential paperwork, (such as pre-immunisation checklists and vaccine side effects forms), equipment to maintain the cold chain, as well as any equipment necessary to prepare and administer vaccines. Remote access to patient records and the Australian Immunisation Register (AIR) is recommended to allow for review of immunisation records. as well as appropriate documentation of any vaccines administered.

Staff:

Staff may include nurse immunisers, as well as medical and administrative personnel.

The cold chain

Storage of vaccines in a drive-through clinic setting must comply with the cold chain recommendations set out by the vaccine manufacturer.  The time between vaccines being removed from purpose-built vaccine fridges to being administered should be as short as possible.

During a drive-through immunisation session

Immunisation history, pre-immunisation checklist, possible vaccine side effects and suitability for immunisation must be reviewed and discussed prior to vaccination.

Emergency equipment (anaphylaxis response kit) and a telephone must be readily available should they be required.

Correct injection technique is essential, ensuring that the entire limb is exposed and correct anatomical landmarks identified to locate the correct injection site. If a patient cannot be safely immunised in the car (eg: child seated in the middle car seat) or is not a suitable candidate for in-vehicle immunisation then they could be immunised out of the car in a chair, then returned to the car to wait for the recommended 15 minute waiting period. Patients should be advised not to get in and out of their cars whilst parked.

Post-immunisation in a drive-though session

Following immunisation, patients must remain at the vaccination venue for at least 15 minutes and should be advised to avoid driving for at least 15 minutes following vaccination. Patients waiting in their vehicles should be instructed to use the car horn to gain attention in their 15 minute observation period if required. All vaccines should be recorded on the AIR and appropriate documentation should be completed and provided to the patient.

Resources

Authors: Francesca Machingaifa (SAEFVIC Research Nurse, Murdoch Children’s Research Institute) and Rachael McGuire (SAEFVIC Research Nurse, Murdoch Children’s Research Institute)

Date: February 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.