How COVID-19 vaccines work

Find out how the COVID-19 vaccines work, how they are approved, how we decide how to use them, and where to go for credible information.

COVID-19 vaccines in Australia

We are using 3 COVID-19 vaccines in our national vaccine rollout:

  1. Comirnaty (Pfizer)
  2. Spikevax (Moderna)
  3. Nuvaxovid (Novavax).

Types of vaccines

There are 2 types of approved vaccines in use:

The vector vaccine AstraZeneca  is no longer being used as part of the national vaccine rollout as it has expired.

Learn more about the science of immunisation.  

Vaccination recommendations

The Australian Technical Advisory Group on Immunisation (ATAGI) advises the Australian Government about the medical administration of vaccines, including COVID-19 vaccines. 

They make recommendations on the use of each COVID-19 vaccine based on research and medical advice. This includes which vaccines are recommended for people in different age groups.

The Australian Government considers ATAGI’s advice when it makes policy decisions about vaccines.

How the vaccines work

These vaccines help prevent people from getting severely ill or dying, from COVID-19. 

The vaccines train your immune system to recognise and clear out the virus, before it makes you seriously ill. Your body's immune system builds this protection over time.

To receive the best protection against serious illness or death from COVID-19, you should stay up to date with all vaccinations recommended for your age or individual health needs.  The virus that causes COVID-19 (called SARS-CoV-2) has spikes of protein on each viral particle. These spike proteins allow the virus to attach to cells and cause disease.

The vaccines help the body to:

  • recognise these spike proteins as a threat
  • fight the coronavirus that has these proteins.


The ATAGI recommended doses and vaccines outlines which vaccines and doses are recommended for each age and population group.

If you have had COVID-19 you should wait to be vaccinated with a COVID-19 vaccine for 6 months after the confirmed infection.

Find out more about third doses for people with severe immunocompromise.

Booster doses

To receive the best protection against serious illness or death from COVID-19, you should stay up to day with all vaccinations recommended for your age. Boosters are important to maintain this protection.

All adults can get a booster if it’s been 6 months or longer since their last COVID-19 booster or confirmed infection (whichever is most recent) for additional protection against severe illness from COVID.

This is particularly recommended for people at higher risk of severe illness, including:

  • everyone 65 years and over
  • everyone 18 years and over with medical comorbidities, disability or complex health needs.

Children and adolescents aged 5 to 17 with health conditions that put them at risk of severe illness can also get a booster dose if it’s been 6 months since their last dose or COVID-19 infection, based on an individual risk assessment with their immunisation provider.

Booster doses are not recommended at this time for children and adolescents aged 18 years or under who do not have any risk factors for severe COVID-19.

All vaccines are approved for use in Australia and continue to provide very strong protection against serious illness from COVID-19, however, Omicron-specific bivalent vaccines are preferred for boosters.

The date you had your last COVID-19 vaccine is on your COVID-19 digital certificate.

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How vaccines are approved

The Therapeutic Goods Administration (TGA) approves vaccines for use in Australia after a careful evaluation process

The COVID-19 vaccines have provisional approval. This means they can be legally used in Australia because the need for early access outweighs the risks. The manufacturers continue to collect data on vaccine safety and efficacy and will apply for full approval later.

The TGA also continuously monitors vaccine safety and side effects

Authoritative vaccine information

There is a lot of information – and misinformation – out there about coronavirus and the COVID-19 vaccines. 

We encourage you to rely on reputable sources to help you make informed choices and stay up to date.

Reputable information about COVID-19 vaccines is available from:

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