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 4 COVID-19 vaccines in our national vaccine rollout:

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

Types of vaccines

There are 3 types of approved vaccines:

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.

Doses

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 3 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.

An additional booster dose, or ‘fourth dose’, is recommended for people at increased risk of severe illness. This additional booster will be a fifth dose for people who are severely immunocompromised, have an underlying medical condition or disability.

You should get a second booster dose if you have had your first booster dose 3 months ago and you are:

  • 50 years or older
  • 16 years or older and a resident of an aged care or disability care facility
  • 16 years or older and severely immunocompromised
  • Aboriginal or Torres Strait Islander and aged 50 years and older
  • 16 years or older with a medical condition that increases the risk of severe COVID-19 illness
  • 16 years or older with a disability.

A fourth dose is also available to people aged 30 to 49 years old if they choose.

People who had COVID-19 after their first booster should wait at least 3 months before having a second booster.

A COVID-19 booster dose is recommended for people aged 5-15 years who:

  • are severely immunocompromised, or
  • have a disability with significant or complex health needs, or
  • have severe, complex, or multiple health conditions that increase the risk of severe COVID-19.

Read more about booster doses for children aged 5 to 11 years and adolescents aged 12 to 15 years.

Find out more about booster doses.

Staying up to date

To be considered up to date with COVID-19 vaccination, you must have completed all the doses recommended for your age and health status.

Find out about how to stay up to date with COVID-19 vaccines.

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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