Vaxzevria (AstraZeneca) can prevent people from becoming ill from COVID-19. Two doses are required as part of the primary course. These 2 doses are usually given 4-12 weeks apart.
The AstraZeneca vaccine can also be used as an additional booster dose, 3 months or more after the primary course, although Comirnaty (Pfizer) or Spikevax (Moderna) are preferred for this booster.
The AstraZeneca vaccine does not contain any live SARS-CoV-2 virus and cannot give you COVID-19. It contains the genetic code for an important part of the SARS-CoV-2 virus called the spike protein. This code is inserted into a harmless common cold virus (an adenovirus), which brings it into your cells. Your body then makes copies of the spike protein, and your immune system learns to recognise and fight the SARS-CoV-2 virus. The adenovirus has been modified so that it cannot replicate once it is inside cells. This means it cannot spread to other cells and cause infection.
Vaccination is voluntary and free. You can discuss any concerns or questions you have about COVID-19 vaccination with your immunisation provider and/or your GP before you receive the vaccine.
AstraZeneca protects people from becoming ill from COVID-19. It particularly prevents severe illness, hospitalisation and death. The vaccine has been shown to be highly effective in both clinical trials (before it was registered for use) and in studies of people vaccinated in the ‘real world’ in England and Scotland.
COVID-19 is a very serious disease which can cause serious illness in people of all ages. It has caused millions of deaths and hundreds of millions of infections worldwide. Vaccination helps protect both individual people and benefits all people in the community by reducing the spread of COVID-19.
A booster dose refers to an additional vaccine dose after the primary vaccine course. It is intended to strengthen and prolong protection against COVID-19.
You are recommended to receive a booster dose if you have completed a primary course of vaccination 3 or more months ago and are:
- 16 years and older, or
- 12-15 years and meet one or more of the following criteria:
- be severely immunocompromised
- have a disability with significant or complex health needs, and/or
- have complex and/or multiple health conditions that increase the risk of severe COVID-19 and have
A booster dose of Pfizer is recommended for people aged 12 -17 years of age who meet one or more of the above criteria.
Booster doses are not recommended for younger people at this stage.
In addition, some people aged over 12 years at high risk of severe illness from COVID-19 are recommended to have a winter booster ( i.e. 5th dose) dose from 4 months after their first booster.
For people aged 18 years and over, Pfizer or Moderna are preferred for the booster dose, including for those who had two doses of AstraZeneca for the primary course. Novavax can also be used as a booster dose.
However, AstraZeneca can be given to people aged 18 years and older who cannot have the Pfizer , Moderna or Novavax vaccines for medical reasons (e.g. severe allergic reaction) or for people who decline an alternative vaccine brand.
For more information on booster and winter doses see: https://www.health.gov.au/initiatives-and-programs/covid-19-vaccines/getting-your-vaccination/booster-doses
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 at: https://www.health.gov.au/initiatives-and-programs/covid-19-vaccines/getting-your-vaccination/stay-up-to-date
People aged 18 years and older can receive AstraZeneca. Pfizer, Moderna are preferred over AstraZeneca in people aged under 60 years. Novavax is also available as a booster. However, AstraZeneca can be used in adults aged under 60 years if Pfizer, Moderna or Novavax are not available and if the person has made an informed decision based on an understanding of the risks and benefits.
As with any vaccine, you may have some temporary side effects after receiving a COVID-19 vaccine.
Common side effects after AstraZeneca include injection site pain or tenderness, tiredness, headache, muscle pain, and fever and chills. Most side effects are mild and temporary, going away within 1-2 days. As with any medicine or vaccine, there may be rare and/or unknown side effects.
AstraZeneca appears to be linked with a very rare side effect called thrombosis with thrombocytopenia syndrome (TTS). TTS involves blood clots (thrombosis) and low levels of blood platelets (thrombocytopenia) and occurs around 4 to 42 days after vaccination. The blood clots can occur in different parts of the body, such as the brain (called cerebral venous sinus thrombosis or CVST) or in the abdomen (idiopathic splanchnic thrombosis).
The mechanism that causes TTS is not fully understood, but it appears similar to heparin-induced thrombocytopenia (or HIT), a rare reaction to heparin treatment.
The rate of TTS reported in Australia and overseas is higher in younger adults and appears more common in women. Cases have also been reported, however, in men and in older people.
TTS is very rare. In Australia, the rate of TTS is estimated to be:
- about 2 per 100,000 people vaccinated with AstraZeneca aged 60 years or older
- about 2 to 3 per 100,000 people vaccinated with AstraZeneca under 60 years of age.
A range of severity of illness has been reported in Australia. Some cases have been relatively mild, some have had significant morbidity, and some have been fatal.
The overall case fatality rate is lower than reported internationally. This is likely to reflect increased detection due to increased awareness, as well as early diagnosis and treatment
Based on current information, we have not identified any pre-existing medical conditions that may contribute to developing TTS or make it worse if it occurs.
If you have had other types of blood clots in the past, such as deep vein thrombosis (DVT) or pulmonary embolism (PE), or if you have risk factors for blood clots, you can still have the AstraZeneca vaccine. There is no evidence that people who have had a history of other types of blood clots have an increased risk of developing TTS or becoming more ill from it if it occurs.
For more information on TTS please see Vaxzevria (AstraZeneca) vaccine and thrombosis with thrombocytopenia (TTS).
An alternative vaccine brand for dose 2 should be used if there are specific medical contraindications or precautions, or if the same vaccine brand is not available in Australia.
Whilst it is preferable to use the same brand for both doses of the primary course, an alternative brand can be used for the second dose for other reasons. Examples include if a person is unable to access the same brand or does not accept a second dose of the same brand.
The risk of TTS is much lower after the second dose and is currently 0.3 in every 100,000 vaccinated people (compared to a risk of 2 in every 100,000 vaccinated people after the first dose).
You should not receive this vaccine if you have had:
- anaphylaxis (a type of severe allergic reaction) to a previous dose of the vaccine
- anaphylaxis after exposure to any component of the vaccine, including polysorbate 80
- a history of capillary leak syndrome
- TTS occurring after a previous dose of the vaccine
- any other serious adverse event, that following review by an experienced immunisation provider/medical specialist, was attributed to a previous dose of the vaccine (and without another cause identified).
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 of a COVID-19 vaccine or to an ingredient of the vaccine
- anaphylaxis to other vaccines or to other medicines. Your provider can check to ensure there are no common ingredients with the COVID-19 vaccine you are receiving
- 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 intramuscular injection and help to decide the best timing for injection.
Pfizer or Moderna are recommended in people who have had one of the following rare causes of blood clots:
- cerebral venous sinus thrombosis
- heparin-induced thrombocytopenia
- idiopathic splanchnic thrombosis
- antiphospholipid syndrome with thrombosis.
People with immunocompromise includes those who have a medical condition that weakens their immune system. It also includes those who may be taking medications that suppress their immune system.
AstraZeneca does not behave like a ‘live vaccine’. The adenovirus carrier has been modified so that it cannot replicate or spread to other cells, and it cannot cause infection. It is safe in people with immunocompromise.
A small clinical trial found that the side effects and immune responses to AstraZeneca were similar in a small group of adults with stable HIV infection, compared with adults without HIV.
We do not know if AstraZeneca is as effective in people with immunocompromise compared to the rest of the population. It is possible that it might be less effective, and so it is important to continue other preventative measures such as physical distancing after vaccination.
For more information on use of the vaccine in immunocompromised.
People over 5 years of age with severe immunocompromise are recommended to have a third dose of Pfizer or Moderna (over 6 years of age) for their primary course.
For people over 18 years of age, Novavax can also be used for this third dose.
Severely immunocompromised people aged 12 years and over who have received a third primary dose may receive a booster dose (i.e. 4th dose) at 3 months following their primary course, in line with the timing for the general population.
Pfizer is recommended for a booster dose those severely immunocompromised between 12-15 years of age.
Pfizer and Moderna are the preferred vaccine in adults under 60 years of age, and women who are pregnant or breastfeeding. You do not need to stop breastfeeding after vaccination. AstraZeneca is not preferred in pregnancy. Pregnant women who have already received a first dose of AstraZeneca can receive either Pfizer, Moderna, AstraZeneca or Novavax for their second dose, although Pfizer or Moderna are preferred.
For more information on use of the vaccine in pregnancy and breastfeeding.
If you have ever had COVID-19 in the past, tell your immunisation provider. You should wait 3 months after a confirmed COVID-19 infection to have a COVID-19 vaccine dose. If you have ongoing illness from COVID-19, discuss the best timing of vaccination with your treating doctor.
If you have been infected and are required to receive COVID-19 vaccination, a temporary medical exemption may be applicable. You should speak with your healthcare provider about what is best for them.
Providers are advised to only provide temporary exemptions for a period of up to 4 months post-infection. This is due to the increased risk of reinfection after this time. AstraZeneca has only been provisionally approved for use in people aged 18 years or older. It cannot be given to people younger than 18.
The TGA assesses all vaccines in Australia. This ensures a vaccine is safe, effective and manufactured to a very high quality standard. A description of the process for approval of COVID-19 vaccines is available here: http://www.tga.gov.au/covid-19-vaccine-approval-process
The safety of COVID-19 vaccines will be monitored continuously throughout the COVID-19 vaccination program. Suspected side effects can be reported to your vaccination provider or other healthcare professional. They will then make a formal report on your behalf to your state or territory health department or directly to the Therapeutic Goods Administration (TGA).
If you would prefer to report it yourself, please visit and follow the directions on the page.
For more information, visit COVID-19 vaccine information in your language or call 1800 020 080.
For interpreting services, call 131 450.