Vaccines and COVID-19

We answer some of your questions about COVID-19 vaccine development | Updated 17 February 2021

Vaccines and COVID-19

The development of an effective vaccine for COVID-19 has been a global public health challenge. The race continues to manufacture and distribute vaccines that are effective and safe, and readily available to billions of people.

NPS MedicineWise would like to thank the NCIRS for their review of this content.

UPDATE 17 February 2021

On 16 February 2021, the Therapeutic Goods Administration (TGA) announced it had granted provisional approval to AstraZeneca Pty Ltd for its COVID-19 vaccine, ChAdOx1-S. This is the second COVID-19 vaccine to receive regulatory approval in Australia.

Provisional approval means that the vaccine has met the high standards of safety, effectiveness and quality required for use in Australia. This allows for temporary registration and inclusion in the Australian Register of Therapeutic Goods (ARTG) for up to two years with an option to extend provisional registration beyond this initial period.

The Australian Government has advised that rollout of the AstraZeneca COVID-19 vaccine will start in March 2021, subject to availability of supply.


UPDATE 25 January 2021

On 25 January 2021, the Therapeutic Goods Administration (TGA) announced they had granted provisional approval to Pfizer Australia for its COVID-19 vaccine, COMIRNATY. This is the first COVID-19 vaccine to receive regulatory approval in Australia.

Provisional approval means that the vaccine has met the high standards of safety, effectiveness and quality required for use in Australia. This allows for temporary registration and inclusion in the Australian Register of Therapeutic Goods (ARTG) for up to two years with an option to extend provisional registration beyond this initial period.

The Australian Government have advised that rollout of the Pfizer vaccine will commence towards the end of February, 2021, subject to availability of supply.

Find out more: Getting vaccinated for COVID-19


Is there a vaccine for COVID-19?

Yes. At the time of publishing there is one COVID-19 vaccine, COMIRNATY, approved for use in Australia.1

COMIRNATY is an mRNA vaccine approved to prevent COVID-19, the disease caused by SARS-COV2, in people aged 16 years and older.

Read more about mRNA vaccines by scrolling down to the section ’How do mRNA vaccines work?’

You can download the Approved Product Information or the Consumer Medicine Information (CMI) for COMIRNATY from the TGA website.

In some countries, including the United Kingdom, United States and Canada, rollout of several COVID-19 vaccines to select groups eg, frontline workers and the elderly, has commenced under interim and/or emergency use agreements.

The number of COVID-19 vaccines in development and being trialled is constantly changing. A snapshot of the vaccine landscape is available on the NCIRS website, with a more in depth summary of trials available through the WHO.

Monitoring of potential vaccines continues

The European Medicines Agency (EMA), and members of the Access Consortium – including Australia, Canada, Singapore, Switzerland and the UK – will continue to evaluate the evidence of each potential vaccine as they prepare for regulatory review.2

The TGA continues to actively monitor COVID-19 vaccine development occurring both in Australia and around the world. In addition to the provisionally approved Pfizer vaccine, the TGA has granted ‘provisional determinations’ in relation to three COVID-19 vaccines in Australia. Find out more about the COVID-19 vaccines undergoing evaluation

Read more about how vaccines are approved on the TGA website COVID-19 vaccine: Information for consumers and health professionals

Read more about provisional determinations on the TGA website.


Why is it taking so long?

Ensuring COVID-19 vaccines are safe and effective takes time. Typically, vaccine development takes about 10 years.3 This is because vaccines must pass a series of pre-clinical studies (usually laboratory based), clinical trials in humans, and approval processes before they become available for use.

The steps of the clinical trial process are known as phases. Any vaccine in development must progress through each testing phase to make sure it is safe and effective.4

Usually the different phases can take months, years or even longer. But due to the urgency of finding a vaccine to prevent SARS-CoV-2 (the virus that causes COVID-19), this process is being fast-tracked.

What happens in each phase of a clinical trial?

Phase I clinical trials are done to test a medicine – in this case a vaccine – for the first time in a small group of people – usually a few dozen healthy volunteers.

A phase I trial works out if the vaccine is safe by evaluating how the human body reacts to the vaccine and observing for any side effects.

Phase II trials usually involve a few hundred people and provide information about how well the vaccine works (efficacy) as well as further information about the safest dose range.

Phase III trials usually involve a few thousand people, testing the efficacy and safety in a larger group.

Before a clinical trial can move to Phase IV, a government regulatory body examines the Phase III results and decides whether to approve the vaccine for use in the general population. In Australia, approval is given by the Therapeutic Goods Administration (TGA).

Phase IV clinical trials are conducted after the product has been approved and involve gathering information about efficacy and safety in the general population.5,6


Which are the leading vaccine candidates?

At the time of publication, nine vaccines had reached regulatory decisions in countries around the word. Two of these - BioNTech/Pfizer mRNA vaccine and Moderna COVID-19 vaccine – are now being administered in high-risk groups in a number of countries.

To keep up to date with the latest in vaccine research and development in Australia and across the globe visit:


Are there any COVID-19 vaccines being developed in Australia?

At the time of writing there are six COVID-19 vaccines with Australian involvement being tested in human clinical trials.4

Two vaccines (Phase I) are being developed and trialled in Australia.4

  • Covax-19 at Flinders University with trials at Royal Adelaide Hospital
  • UQ-CSL V451 at the University of Queensland*

The other four vaccines are being trialled in Australia but were developed overseas (see summary table).

Table 1. COVID-19 vaccines with Australian involvement4


Research Group/Developer

Vaccine platform

Trial locations



Flinders University/ Vaxine (Australia)





(SARS-CoV-1 S Clamp)

University of Queensland/ CSLa





Clover Biopharmaceuticals




Novavax (USA)


Melbourne and Brisbane


Novavax (USA)


10 locations across the ACT, NSW, QLD, Victoria, and 8 locations in the US



SpyBiotech (USA)

Virus like particle




Symvivo (Canada)




a On 11 December 2020, the University of Queensland and CSL announced that the UQ-CSL V451 COVID-19 vaccine would not progress to Phase II/III clinical trials. Results from the UQ Phase I trial showed that the vaccine was both effective and safe, however it was found that the immune response to a component of the vaccine interfered with HIV test results in some patients.7

The UQ-CSL vaccine cannot infect someone with HIV or cause AIDS.7


How many COVID-19 vaccines are in Phase III?

In January 2021 there were more than 200 COVID-19 vaccines in development globally, with over 60 vaccines at the clinical trial stage.

Of these, fifteen COVID-19 vaccines were in Phase III.4

Interim results for two of the vaccines currently in Phase III trials were published in early December 2020.8,9 Findings for these trials reported that:

  • two doses of the Pfizer/BioNTech (BNT162b2) vaccine, given 21 days apart, were 95% effective in preventing laboratory-confirmed COVID-19, compared with placebo injections. Side effects included mild to moderate pain at the injection site, fatigue and headache, with low incidence of serious side effects.
  • two doses of the University of Oxford/AstraZeneca (ChAdOx1 nCoV-19) vaccine, were around 70% effective in preventing laboratory-confirmed COVID-19, compared with a control injection (either placebo or meningococcal vaccine depending on trial group). The results of this study were complicated by a number of factors and further research data is needed to gain a clearer picture of the true effectiveness of the vaccine. Several serious side effects were reported (in both vaccine and control groups) and the trial was paused while these were investigated. Investigators found that the majority of the serious effects were unlikely to be vaccine-related.

Not all vaccines that enter the early phases of a clinical trial will progress to Phase II/III or make it to ‘market’ ie, be approved for public sale and distribution.5 

For up-to-date information about the progress of COVID-19 vaccines visit the NCIRS website.

A more in depth summary of clinical trials is available for download from the WHO.


Will Australians have access to these vaccines?

Since October 2020, the TGA has granted four ‘provisional determinations’ allowing pharmaceutical company sponsors to submit comprehensive clinical data about their COVID-19 vaccines.

Provisional determinations are the first step in the approval process, however they do not mean that the vaccine will be approved.

Table 2. Provisional determinations granted by the TGA from October to November 202010

Effective date

Pharmaceutical company/sponsor

Name of vaccine

Type of vaccine

9 October 2020


ChAdOx1-S [recombinant]

viral vector

14 October 2020

Pfizer Australia

BNT162b2 [mRNA]b


16 November 2020



viral vector

19 January 2021

Biocelect (on behalf of Novavax)



b Provisional approval granted by TGA on 25 January 2021 for BNT162b2 mRNA (COMIRNATY)

Australia’s vaccine agreements

The Australian Government has entered into four separate agreements for the supply of COVID-19 vaccines, if they are proved to be safe and effective. The investment of more than $3.3 billion through these 4 agreements mean the Australian public are in a good position to access safe and effective vaccines once they are available.11

For up to date information on Australia’s vaccine agreements visit the Australian Government Department of Health website.


How much will it cost to vaccinate everyone?

It is estimated that the cost of vaccinating all 25 million Australians against COVID-19 will be between $125 million and $5 billion a year.12


Will a vaccine offer immunity to COVID-19?

Vaccines stimulate the body’s natural defences to strengthen the immune system response to a condition or illness.13

Vaccines use inactivated or severely weakened pathogens such as viruses or bacteria to trick the immune system into producing antibodies. Viral vaccines help your body fight off viruses. After receiving a viral vaccine, the body’s immune system recognises and remembers the virus.13

Then, if a person is exposed to the virus later on, their immune system can fight off an infection much more effectively because it has already produced antibodies to that virus.13,14

Viral vaccines can work in two ways. In some instances, they can prevent infection.

At other times, people can still become infected with the virus, but the antibodies produced as a result of the vaccine can significantly reduce the severity of symptoms and stop people from getting very sick.13,14

It is important to note that not all vaccines provide long-lasting immunity. Protection against a virus can decrease over time. This is why booster doses are needed in some circumstances, such as with the tetanus vaccine.15

Based on what is currently been reported for the COVID-19 vaccines under investigation, booster doses may be needed to ensure people keep their immune memory and their immune systems remember how to fight the SARS-CoV-2 virus for as long as possible.16


Why is there more than one COVID-19 vaccine?

Even though COVID-19 vaccines are being developed to guard against the same virus (SARS-CoV-2), they are not all the same.

Different research groups have different methods for researching and developing vaccines.

Some research groups are focusing on the whole SARS-CoV-2 virus, while other groups are concentrating on the proteins that are produced by the virus.17

There are several methods – also known as technologies or platforms – used to develop viral vaccines.

In the race to develop a COVID-19 vaccine, the commonly used methods include:15,18-20

  • live attenuated vaccines, like the vaccine used for measles-mumps-rubella (MMR)
  • inactivated vaccines, like the vaccine used for hepatitis A
  • protein subunit vaccines, like the vaccine used for hepatitis B
  • virus-like-particles, like the vaccine against human papillomavirus (HPV)
  • viral vector and nucleic acid (DNA or RNA, including messenger or mRNA). 

How do mRNA vaccines work?

Traditional vaccines contain either inactivated or weakened viruses, or virus proteins that signal the immune system to recognise the part of the virus that causes disease.21,22

Messenger RNA (or mRNA) vaccines work differently to traditional vaccines. An mRNA vaccine does not contain viral protein. Instead the vaccine contains key genetic instructions (mRNA) so our body knows how to make a particular viral protein itself.

COVID mRNA vaccines are injected into the muscle of the upper arm. These muscle cells read the instructions and build a part of the SARS-CoV-2 virus known as the ‘spike protein’. Once the protein is made, the instructions are broken down and destroyed. The newly built spike protein is seen by the immune system as not belonging to us, and antibodies to that spike are made. If a person vaccinated with the mRNA vaccine is infected with SARS-CoV-2 in the future, the spike proteins on the live virus will be recognised by their immune system and more antibodies will be made to stop the virus from causing an infection.21,22

You can find out more about vaccine platforms on the National Centre for Immunisation Research and Surveillance (NCIRS) website.


Is it safe to test the COVID-19 vaccine on people?

All vaccines, including COVID-19 vaccines, are rigorously tested in human clinical trials to confirm they are safe and effective before they can be used.23

When it comes to testing COVID-19 vaccines, it’s important to emphasise that the people who are involved in the clinical trials:

  • are mostly healthy volunteers (although some may have other health conditions not related to COVID-19)
  • are not intentionally infected with COVID-19 to test if the vaccines work.

Viral vaccines use inactivated or severely weakened viruses, or parts of viruses that trick the immune system into producing antibodies.13 In this case, it is expected that the person who is receiving the COVID-19 vaccine will produce antibodies to the SARS-CoV-2 virus.

All volunteers must undergo a thorough health assessment before they can be included in a clinical trial.

As with any medicine, vaccines may cause side effects, and these are closely monitored throughout all phases of the clinical trials.5


Will the COVID-19 vaccine be safe for all ages?

Vaccines are initially tested in young, healthy adults, before being tested on more vulnerable people, such as children, older adults and pregnant women.

Vaccine trials in children usually occur in a stepwise process referred to as age de-escalation, starting with adolescents and older children, followed by younger children, and finally, babies.

This allows us to gather important age-specific information about the safety and efficacy of a vaccine in different age groups.

Trials in healthy volunteers will give us confidence that the vaccine is safe for use in the larger general population.


What if I’m allergic to the COVID-19 vaccine?

Severe allergic reactions (anaphylaxis) to vaccines are very rare.24 Doctors and nurses who administer vaccinations are trained to recognise and manage any immediate, severe reactions.25

If anaphylaxis does occur, it is generally within the first 15 to 20 minutes after receiving a vaccine, so it is important for people to wait at the place they get their vaccination so they can be observed for any reaction.25

Most vaccines do not contain food allergens such as dairy products, peanut, tree nuts, wheat, soy, seeds or seafood.24

Allergic reactions to vaccines are more often caused by vaccine components such as gelatin or egg protein, yeast, or the latex parts of vial lids, or syringe plungers rather than the actual vaccine.26

Before any vaccine is given, a safety checklist is performed with the patient to make sure they do not have any allergies to components of the vaccine.


What are the possible side effects of vaccination?

Generally, side effects from vaccination are usually mild and short lasting and do not need special treatment.

Common reactions to vaccination can include:25

  • injection site reactions such as local pain, redness and swelling
  • mild temperature or fever
  • irritability
  • decreased appetite
  • sleepiness
  • vomiting and diarrhoea
  • light headedness or fainting (uncommon, but this can occur before or after vaccination).

Do I still need to get the flu vaccination?

Yes. While the influenza vaccination won’t protect you against COVID-19 it will reduce your risk of the flu. Getting the flu vaccine will help to provide greater individual and community health protection throughout the COVID-19 pandemic.27

In Australia, complications from influenza lead to thousands of hospitalisations and many deaths every year.

If a person catches COVID-19 on top of the flu, it is likely they will become severely sick or die, especially if they are elderly or their immune system is weaker.

Having the flu vaccination will help to protect vulnerable people from getting the flu. And reducing hospitalisations from the flu will ease pressure on the health system so health workers can focus on people who present with COVID-19.27


Will a COVID-19 vaccine mean no more physical distancing or handwashing?

Once a COVID-19 vaccine is available to the general public, it is unlikely to be the ‘silver bullet’ everyone is hoping it might be.12

We don’t know if everyone will respond the same way to a vaccine, whether they will experience side effects or have long lasting immunity to COVID-19.

Physical (social) distancing, regular handwashing, choosing to wear a mask in public and changes to the way we travel may be here for a while longer.16


Where can I learn more?

Find out more about vaccines

The National Centre for Immunisation Research and Surveillance (NCIRS) is closely monitoring information on COVID-19 vaccine candidates and updates this information weekly. Visit NCIRS COVID-19 vaccine development landscape.

Register for a vaccine trial

If you are healthy and interested in taking part in a vaccine trial you can find out more at NCIRS: Upcoming COVID-19 vaccine trials



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  25. Jo Ann Faber. Patients with vaccine allergy may be safely vaccinated following new guidelines. Illinois,: American College of Allergy Asthma & Immunology, 2020 Accessed 9 September 2020).
  26. Australian Medical Association (AMA). Early flu vaccine the best protection aginst COVID-19. Canberra: Australian Medical Association Limited, 7 April 2020 (accessed 8 September 2020).