Vaxzevria (AstraZeneca)

Find out more about the AstraZeneca vaccine, including how it works, who it's recommended for and advice about potential side effects.

Approval for use in Australia

Vaxzevria (AstraZeneca) is approved and available for use as a primary course and booster dose in people aged 18 years and over. 

The TGA provisionally approved it for use in Australia as a primary course on 15 February 2021.

The TGA provisionally approved for use in Australia as a booster on 8 February 2022.

Pfizer, Moderna, or Novavax COVID-19 vaccines are preferred over AstraZeneca for people aged under 60 years. This is based on the higher risk and observed severity of a rare side effect called thrombosis with thrombocytopenia (TTS) after receiving AstraZeneca in people aged under 60 years compared with people aged 60 years or older.

There is no brand preference for people aged 60 years and older. People aged 60 years or older are at higher risk of severe illness from COVID-19, meaning the benefits of vaccination outweigh the very small risk of TTS.

AstraZeneca can be used in adults aged under 60 years if the person has made an informed decision based on an understanding of the risks and benefits.

Dose schedule

Primary course

For most people the AstraZeneca primary course is 2 doses,  4 to 12 weeks apart. 

Most people have their second dose 12 weeks after their first, but it can be less time in certain situations.

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. AstraZeneca is not preferred for this third dose but can be used in adults if there are contraindications to mRNA and Novavax COVID-19 vaccines. The third primary dose is usually given 8 weeks after the second dose of the primary course.

Find out more about third doses for people who are severely immunocompromised.

Booster doses

AstraZeneca can also be used as a booster dose in people aged 18 years and older. The booster dose is given 3 months or more after the primary course.

Some people are also recommended to have a second booster dose (fourth dose) 3 months after the first booster.

mRNA vaccines (Pfizer or Moderna) are the preferred vaccines for booster doses, regardless of which vaccine was used for the primary course.

Although not preferred, AstraZeneca can be used as a booster dose for:

  • people who have a contraindication to mRNA vaccines (including those who have had a serious adverse event following mRNA vaccines, such as a history of anaphylaxis or myocarditis attributed to an mRNA vaccine)
  • people who do not prefer an mRNA vaccine

Find out more about booster doses.

If you have had COVID-19, you should wait to be vaccinated with a COVID-19 vaccine 3 months after your confirmed infection.

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.

What's in the AstraZeneca vaccine

The AstraZeneca vaccine uses a harmless, weakened animal virus (called a viral vector) that contains the genetic code for the coronavirus spike protein. Once this enters the body, it tells your cells to make copies of the spike protein. Your immune cells then recognise the spike protein as a threat and begin building an immune response against it.

The AstraZeneca vaccine does not contain any live virus, and it cannot give you COVID-19. 

You can read the full Vaxzevria 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 AstraZeneca outweigh the risk of side effects for people 60 years and older, and younger people in outbreak situations.

A very large clinical trial showed that AstraZeneca is effective in preventing COVID-19 in people aged 18 years and older. People who had 2 doses of AstraZeneca were about 70% less likely to get ill from COVID-19 than people who did not get the vaccine. It was also effective in people with some stable pre-existing medical conditions.

Common side effects

AstraZeneca 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 the AstraZeneca vaccine. This shows your immune system is working.

Common side effects after the AstraZeneca vaccine include:

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

Less common side effects after AstraZeneca vaccine include:

  • enlarged lymph nodes
  • pain in arm or leg
  • dizziness
  • decreased appetite
  • stomach pain.

Most side effects are mild and go away within 1 to 2 days. They are more common after the first dose of the AstraZeneca vaccine.

Rare side effects

Rare side effects after the AstraZeneca vaccine are severe allergic reaction (anaphylaxis), a specific type of blood clots called thrombosis with thrombocytopenia syndrome (TTS), myocarditis and pericarditis. 

Thrombosis with thrombocytopenia syndrome (TTS)

TTS involves blood clots (thrombosis) together with low levels of blood platelets (thrombocytopenia). It is different from more common types of blood clots.

TTS can occur at different parts of the body, including the brain and in the abdomen (belly). The low level of blood platelets can potentially cause bleeding.

TTS seems to occur:

  • symptoms of TTS most commonly develop 4 to 42 days after vaccination.
  • Predominantly after the first dose
  • More often in younger women.

See a doctor immediately if you develop any of the following symptoms: 

  • severe or persistent headache that does not go away after taking pain relief medication
  • blurred vision
  • confusion or seizure
  • weakness of face or limbs
  • shortness of breath or chest pain
  • severe abdominal (belly) pain
  • Leg swelling
  • Unexplained pin-prick rash or bruising away from the injection site 

TTS can be treated very effectively and most people recover. 

Read more in our fact sheet Information on COVID-19 AstraZeneca vaccine.

The Melbourne Vaccine Education Centre has a page on TTS that includes an explanatory video. 

Low risk of developing TTS

In Australia, the risk of developing TTS after a first dose of AstraZeneca is around 20 in a million. 

Fact sheets on TTS

Find out more about TTS.

We have printable fact sheets on TTS for doctors.

The Melbourne Vaccine Education Centre has a page on TTS that includes an explanatory video.

Injection technique unlikely to cause TTS

ATAGI does not consider injection technique to cause adverse events for several reasons.

  • Most cases of TTS only happen after the first dose. If accidentally injecting into a blood vessel was a factor, cases would occur equally after both doses.
  • Directly injecting into a blood vessel is unlikely in the recommended injection sites.
  • TTS typically occurs some days or even weeks after vaccination. If it was caused by injecting into the blood stream instead of a muscle, it would occur much earlier.

Myocarditis and pericarditis

Myocarditis (inflammation of the heart) and pericarditis (inflammation of the membrane around the heart) can occur after AstraZeneca. Cases have been reported in post-licensure use internationally.

These rare effects on the heart typically occur:

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

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 Moderna 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. 

The risk of developing myocarditis and pericarditis is lower after AstraZeneca than after mRNA vaccines (Pfizer or Moderna). Data from the United Kingdom indicate a rate after AstraZeneca of 16 cases per million doses after dose 2 in young people aged 18 to 29 years.

Fact sheets 

Find out more about myocarditis and pericarditis.

We also have a printable guidance on myocarditis and pericarditis after 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 the AstraZeneca COVID-19 vaccine
  • anaphylaxis to other vaccines or to other medications – your provider can check that there are no common components with the AstraZeneca 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 AstraZeneca 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.

You can still get vaccinated with AstraZeneca if you have a:

Pregnant women are offered Pfizer, Moderna, or Novavax as first choice, but can have AstraZeneca if the benefits outweigh the risks for them. 

Groups who should not have AstraZeneca

ATAGI has recommended some people not be vaccinated with the AstraZeneca vaccine.

Contraindications to AstraZeneca are:

  • anaphylaxis after a previous dose
  • anaphylaxis to any component of the vaccine, including polysorbate 80
  • history of capillary leak syndrome
  • thrombosis with thrombocytopenia occurring after a previous dose
  • any other serious adverse event, that following review by an experienced immunisation provider or medical specialist was attributed to a previous dose of the AstraZeneca vaccine.

ATAGI have also advised that people with a history of one of the following specific blood conditions should not receive the AstraZeneca vaccine:

  • cerebral venous sinus thrombosis (CVST)
  • heparin-induced thrombocytopenia (HIT)
  • idiopathic splanchnic (mesenteric, portal and splenic) venous thrombosis
  • anti-phospholipid syndrome with thrombosis.

People who develop immune thrombocytopenia (ITP) within 42 days after receiving AstraZeneca should consult a haematologist about whether to proceed with the second dose using the same or an alternative vaccine, and the timing of the second dose.

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 Novavax, 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 the AstraZeneca vaccine and what to expect after your shot. 

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