Comirnaty (Pfizer)

Find out more about the Pfizer COVID-19 vaccine, including how it works, who it's recommended for and potential side effects.

Information on this page has been superseded by new ATAGI advice on the preferential use of bivalent COVID-19 vaccines for primary course and will be updated shortly.

Approval for use in Australia

Comirnaty (Pfizer) is approved and currently available for use as a primary course in people aged 5 years and over.

Pfizer is approved and available for use as a booster in people aged 12 years and over.

The TGA provisionally approved it for use in Australia on:

  • 25 January 2021 (primary course – for 16 years and over)
  • 25 June 2021 (primary course – for 12 years and over)
  • 26 October 2021 (booster – for 18 years and over)
  • 3 December 2021 (primary course – for 5 years and over) (5 to 11 year formulation)
  • 27 January 2022 (booster – for 16 years and over)
  • 8 April 2022 (booster – for 12 years and over)
  • 29 September (primary course for 6 months to under 5 years)

  • 28 October 2022 (bivalent booster for 18 years and over).

Pfizer’s bivalent COVID-19 vaccine

On 28 October, the TGA provisionally approved Pfizer’s bivalent COVID-19 vaccine for use as a booster dose in adults 18 years and over. 

The Australian Technical Advisory Group on Immunisation (ATAGI) has provided a recommendation that the Pfizer bivalent vaccine can be used as an alternative vaccine for any booster dose in people aged 18 years or older, according to the current ATAGI recommendations for booster doses.

The Pfizer bivalent COVID-19 vaccine targets the original 2020 strain and the Omicron variant BA.1.  

Compared to the original vaccines, ATAGI found it triggers a modest improvement in the immune response against both strains. However, both the bivalent and original vaccines provide significant protection from severe disease against Omicron subvariant infections.

Dose schedule

Primary course

For most people the Pfizer primary course is 2 doses, 8 weeks apart.

For children aged 6 months to under 5 years, the primary course is 3 doses, 8 weeks apart.

It is preferable to have the first 2 doses 8 weeks apart, but the dose interval between doses can be reduced to 3 weeks. A shorter interval may be recommended for people at higher risk of severe COVID-19 (including older adults and people with underlying medical conditions), or before international travel.

You may not be fully protected against COVID-19 until 7 to 14 days after your second dose. Some people who are severely immunocompromised are recommended to have a third dose as part of their primary course. Pfizer can be used for this third dose. It is usually given 8 weeks after the second dose of the primary course.

Booster doses

Pfizer can also be used as a booster dose in people aged 5 years and older. The booster dose is given 6 months or more after the last dose or COVID-19 infection, whichever is more recent.

Read the latest advice and recommendations for booster doses.

Pfizer vaccine for 5 to 11 year olds

The Therapeutic Goods Administration (TGA) has provisionally approved the Comirnaty (Pfizer) vaccine for children aged 5 years and over .

Vaccinating children can help protect children from getting seriously ill or dying from COVID-19. 

Find out more information on COVID-19 vaccines and children.

What's in the Pfizer vaccine

Pfizer is a messenger RNA (mRNA) vaccine. This type of vaccine uses a genetic code called RNA to make your body's cells produce the coronavirus’ specific spike protein.

Your immune system cells then recognise the spike protein as a threat and begin building an immune response against it. The RNA from the vaccine does not change your DNA in any way, and your body quickly breaks it down. 

Pfizer does not contain any live virus and it cannot give you COVID-19. 

This video from John Hopkins Bloomberg School of Public Health explains how mRNA vaccines work. 

You can read the full Comirnaty (Pfizer) Consumer Medicine Information document on the TGA site for more details (click 'I accept' to see the PDF). 

Benefits of vaccination

The benefits of vaccination with Pfizer greatly outweigh the risk of side effects.  

A very large clinical trial showed that Pfizer is effective in preventing and protecting against serious illness from COVID-19 in people aged 12 years and older. People who had 2 doses of Pfizer were about 95% less likely to get ill from COVID-19 than people who did not get the vaccine. It was equally effective in people over the age of 65 years, as well as people with some stable pre-existing medical conditions.

Common side effects

Pfizer is a very safe vaccine. It has been given to millions of people around the world.

As with any vaccine, you may have some temporary side effects after receiving Pfizer. This shows your immune system is working.

Common side effects after Pfizer include:

  • injection site pain or swelling
  • tiredness
  • headache
  • muscle or joint pain
  • fever and chills.

Less common side effects after the Pfizer vaccine include:

  • redness or swelling at the injection site
  • nausea
  • enlarged lymph nodes
  • feeling unwell
  • pain in arm or leg
  • insomnia

Most side effects are mild and go away within 1 to 2 days. AusVaxSafety data shows that side effects are more common after the second dose. 

Rare side effects

Rare side effects after the Pfizer vaccine are severe allergic reaction (anaphylaxis), myocarditis and pericarditis. 

Myocarditis or pericarditis

In rare cases, myocarditis (inflammation of the heart) and pericarditis (inflammation of the membrane around the heart) can develop after vaccination with Pfizer. 

Most cases have mild symptoms and recover well. 

The TGA reports that these rare effects on the heart typically occur:

  • within 1 to 5 days of vaccination
  • predominantly after the second dose
  • more often in men aged under 40.

But they can occur in any gender, at any age, and after any dose.

Contact a doctor or go to hospital immediately if you develop any of the following symptoms after a Pfizer vaccination: 

  • chest pain
  • pressure or discomfort in the chest
  • irregular, skipped heartbeats or ‘fluttering’
  • fainting
  • shortness of breath
  • pain when breathing.

Low risk of developing myocarditis or pericarditis

The risk of developing myocarditis or pericarditis is very low.

In the US, reported rates in males were 10 cases per million after first doses, and 67 cases per million after second doses. The TGA is monitoring the risk in the Australian population.

The risk in children aged 5 to 11 years is not yet known. The clinical trial in children aged 5 to 11 years did not have enough participants to assess rates of myocarditis or pericarditis following the Pfizer COVID-19 vaccine, but no specific safety concerns have been identified so far from millions of doses of this vaccine administered overseas to children aged 5 to 11 years. The benefits of vaccination outweigh this very rare risk, and vaccination is still recommended for all eligible age groups.  

Fact sheets

You can find out more about myocarditis and pericarditis and COVID-19 vaccines here.

We have printable guidance on myocarditis and pericarditis after mRNA COVID-19 vaccines for providers. 

The Melbourne Vaccine Education Centre has a page on myocarditis and pericarditis that includes an explanatory video.

Use in particular groups

People with certain conditions may need additional precautions such as staying for 30 minutes of observation after having their vaccine or consulting an allergy specialist. Tell your immunisation provider if you have had:

  • an allergic reaction to a previous dose or to a component of an mRNA COVID-19 vaccine (Pfizer or Moderna)
  • anaphylaxis to other vaccines or to other medications – your provider can check that there are no common components with the Pfizer vaccine.
  • Confirmed mastocytosis with recurrent anaphylaxis that requires treatment.

If you have a bleeding disorder or you are taking a blood-thinning medication (anticoagulant), tell your immunisation provider. Your immunisation provider can help determine whether it is safe for you to have an injection in your muscle and help decide the best timing for injection.

People with a history of any of the following can receive Pfizer, but talk to your GP, immunisation specialist, or cardiologist about the best timing of vaccination and whether any additional precautions are recommended:

  • Recent (i.e. within the past 3 months) myocarditis or pericarditis
  • Acute rheumatic fever or acute rheumatic heart disease (with active myocardial inflammation)
  • Acute decompensated heart failure.

People who develop myocarditis and/or pericarditis after a COVID-19 vaccine should defer further doses and discuss options for further COVID-19 vaccination with their treating doctor.

Pfizer is safe and effective for:

  • People who are immunocompromised
  • People who are pregnant, breastfeeding or planning pregnancy.

People who should not have the Pfizer vaccine

It's not recommended that you have the Pfizer vaccine if you have had:

  • a severe allergic reaction (anaphylaxis) to a previous dose of the vaccine
  • anaphylaxis after exposure to any component of the vaccine, including polyethylene glycol (PEG)
  • myocarditis and/or pericarditis attributed to a previous dose of the vaccine
  • any other serious adverse event attributed to a previous dose of an mRNA(Pfizer or Moderna) vaccine.

After your COVID-19 vaccination

Find out what to do after you are vaccinated for COVID-19, including how to get your vaccination certificate, what you need to do to stay safe, and what to do if you have side effects.

If you have been vaccinated with Pfizer, you should still get a COVID-19 test if you have symptoms that meet testing criteria according to your local health authority (such as fever, cough, or sore throat).

Patient information

Our patient resources include fact sheets about Pfizer and what to expect after your vaccine. 

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