Updated advice on COVID-19 AstraZeneca vaccine

Following a review of the use of the COVID-19 AstraZeneca vaccine by the Australian Technical Advisory Group on Immunisation (ATAGI) and the Therapeutic Goods Administration, the following recommendations have been made and accepted by the Australian Government:

  • ATAGI recommends that the COVID-19 vaccine by Pfizer is preferred over COVID-19 Vaccine AstraZeneca in adults aged under 50 years. This recommendation is based on the increasing risk of severe outcomes from COVID-19 in older adults, and a potentially increased risk of thrombosis with thrombocytopenia following AstraZeneca vaccine in those under 50 years.
  • COVID-19 Vaccine AstraZeneca can be used in adults aged under 50 years where the benefits are likely to outweigh the risks for that individual and the person has made an informed decision based on an understanding of the risks and benefits.
  • People who have had the first dose of COVID-19 Vaccine AstraZeneca without any serious adverse effects can be given the second dose, including adults under 50 years.

Read the statement from the Department of Health Secretary and Chief Medical Officer.

What is this new side effect?

The clotting syndrome that has been linked to the AstraZeneca vaccine is extremely rare, affecting an estimated four to six people for every million people who receive the first dose of the vaccine.

Thrombosis is the formation of a blood clot, which prevents blood flowing normally through the body.

Thrombocytopenia is a condition in which you have a low blood platelet count. Platelets (thrombocytes) are blood cells that help blood clot. Platelets stop bleeding by clumping and forming plugs in blood vessel injuries.

Thrombosis with Thrombocytopenia Syndrome (TTS) is a rare and new syndrome which has been reported after being given the AstraZeneca COVID-19 vaccine. It may be caused by this vaccine. The condition involves blood clots (occurring in body sites like the brain or abdomen) together with low platelet levels.

TTS occurs between four and 20 days after the first dose of vaccine.

Why has ATAGI made this recommendation?

There is evidence of a likely link between the AstraZeneca vaccine and an extremely rare blood clotting syndrome (thrombosis with thrombocytopenia).

This condition seems to only affect four to six people in every million people who receive the vaccine, and some evidence suggests the risk of this condition occurring may be somewhat higher in people of a younger age, however a small number of cases have been reported in people of different ages (including older adults).

When balanced with the fact that older people have a higher risk of complications from COVID-19, and potentially a lower of risk of developing this extremely rare clotting syndrome, ATAGI is recommending that people over 50 should still receive the AstraZeneca vaccine.

Younger people with certain underlying medical conditions are also at increased risk of severe outcomes from COVID-19, which affects their individual benefit-to-risk balance and may result in a recommendation that they be given the AstraZeneca vaccine to protect them from COVID-19.
For people under 50, the Pfizer vaccine is recommended over the AstraZeneca vaccine.

The Pfizer COVID-19 vaccine does not appear to carry a risk of causing the clotting syndrome.

Is the AstraZeneca vaccine safe?

Yes. The individual benefit-to-risk balance of vaccination with the AstraZeneca COVID-19 vaccine varies with age. This balance is based on factors including the increased risk of complications from COVID-19 with increasing age and the potential lower risk of this very rare, but serious, adverse event with increasing age.

ATAGI has advised the AstraZeneca vaccine remains safe and is recommended to be given to people aged 50 years and over, and may be given to people under 50 if the benefits clearly outweigh the risks.

I’ve had an AstraZeneca vaccine within the last three weeks – what should I do?

The clotting syndrome that has been linked to the AstraZeneca vaccine is extremely rare, affecting an estimated four to six people for every million people who receive the first dose of the vaccine.

The clotting condition occurs between four and 20 days after the first dose of vaccine.

You may experience some side effects following vaccination. Most side effects last no more than a couple of days and you will recover without any problems.

Common reactions to vaccination include pain, redness and/or swelling where you received the needle, mild fever, headache and flu-like symptoms.

Serious reactions such as allergic reactions are extremely rare.

Use the COVID-19 vaccine side effects symptom checker if you have concerns about any symptoms after your vaccine. The checker is also available through the National Coronavirus Helpline on 1800 020 080, 24 hours a day.

See your doctor or health care professional as soon as possible or go directly to a hospital if:

  • you have a reaction that you consider severe or unexpected
  • you are concerned about your condition after vaccination.

People should seek medical attention immediately if they experience any of the following symptoms:

  • shortness of breath
  • chest pain
  • swelling in your leg
  • persistent abdominal (belly) pain
  • neurological symptoms, including severe and persistent headaches or blurred vision
  • tiny blood spots under the skin beyond the site of injection.

If you go to your GP or a hospital with any concerns, please let them know that you have recently had the AstraZeneca vaccine.

If you’ve had your first dose of the AstraZeneca vaccine without developing this condition, then you can safely receive your second dose regardless of your age.

I’ve had my first dose of AstraZeneca, can I switch to Pfizer for my second dose?

To be fully vaccinated against COVID-19 you must have two doses of the same vaccine.
If you’ve had your first dose of the AstraZeneca vaccine without developing Thrombosis with Thrombocytopenia Syndrome (TTS) or experiencing another serious adverse event, then you can safely receive your second dose regardless of your age.

The updated advice regarding the AstraZeneca vaccine is a precautionary decision in response to evidence of a likely link between the AstraZeneca vaccine and an extremely rare blood clotting syndrome. This syndrome appears in people after their first dose of the AstraZeneca vaccine.

What if I don’t want my second dose of AstraZeneca?

Getting vaccinated is not mandatory. However, we strongly encourage you to get vaccinated as COVID-19 can cause serious ongoing health conditions, and sometimes death.

To be fully vaccinated against COVID-19 you must have two doses of the same vaccine.

If you’ve had your first dose of the AstraZeneca vaccine without developing Thrombosis with Thrombocytopenia Syndrome (TTS) or experiencing another serious adverse event, then you can safely receive your second dose regardless of your age.

What is a serious adverse event?

A serious adverse event after a vaccination:

  • is life-threatening
  • requires in-patient hospitalisation or prolongs existing hospitalisation
  • results in persistent or significant disability/incapacity
  • requires intervention to prevent one of the outcomes above.

If you think you’ve experienced a serious adverse event, please speak to your GP or vaccine provider.

I’m booked in for my first dose of the AstraZeneca COVID-19 vaccine, what do I do?

If you are 50 years of age or older, you can still receive your AstraZeneca COVID-19 vaccine.

If you’re under 50, you should only receive a first dose of AstraZeneca COVID-19 vaccine where the benefit of receiving the vaccine clearly outweighs the risk in your individual circumstance.

You may wish to discuss your individual benefit-to-risk balance with your doctor.

Your vaccine provider will likely contact you to speak to you about your appointment.

Generally, if you have not already received a first dose of the AstraZeneca COVID-19 vaccine, then the Pfizer COVID-19 vaccine is preferred in people under 50 years.

In some cases, people who have already booked in for an appointment will need to be provided with a different vaccine. As some clinics only provide one type of vaccine, this may result in a delay in vaccination.

Information about how to receive the Pfizer COVID-19 vaccine will be available shortly.

Should I cancel my appointment?

If you are considering cancelling your appointment, please speak to your vaccine provider first to seek advice.

If you’re under 50, your vaccine provider will likely contact you to discuss your upcoming appointment.

In some cases, people who have already booked in for an appointment will need to be provided with a different vaccine. As some clinics only provide one type of vaccine, this may result in a delay in vaccination.

Information about how to receive the Pfizer COVID-19 vaccine will be available shortly.

If you’re over 50, you can still receive your AstraZeneca COVID-19 vaccine.

Why is AstraZeneca still recommended for people over 50?

It is important to note the AstraZeneca vaccine remains highly effective at preventing death and severe illness among people who have contracted COVID-19 – and that the incidence of the blood-clotting syndrome is very rare.

ATAGI has advised the AstraZeneca vaccine remains safe and is recommended to be given to people aged 50 years and over, and may be given to people under 50 if the benefits clearly outweigh the risks.

While Australia currently has very low or no community transmission of COVID-19, this could change. The risk of serious disease and death in Australia remains, even as border controls and other measures continue.

The individual benefit-to-risk balance of vaccination with the AstraZeneca COVID-19 vaccine varies with age. This balance is based on factors including the increased risk of complications from COVID-19 with increasing age and the potential lower risk of this very rare, but serious, adverse event with increasing age.

If I’m on the pill or already susceptible to blood clots for another reason, am I at a higher risk of developing TTS?

So far no specific biological risk factors or pre-existing medical conditions have been found to modify (i.e. increase or decrease) the risk of Thrombosis with Thrombocytopenia Syndrome TTS occurring after AstraZeneca vaccine. However, if you have any concerns, you should discuss them with your doctor.

While there have been more reports of TTS in women in some settings, this may be because more vaccine doses have been given to women. In one country the reported rate of TTS (number of cases adjusted for the number of men and women vaccinated) was similar in men and women.

ATAGI recommends that vaccination with any COVID-19 vaccine should be deferred for people who have a confirmed medical history of cerebral venous sinus thrombosis (CVST) or heparin induced thrombocytopenia (HIT).

I’m eligible to get the vaccine now, but I’m under 50 – what do I do?

If you’re eligible to get the vaccine now, you should speak to your doctor about what’s best for you.

The AstraZeneca vaccine can be used in people under 50 years where the benefits are likely to significantly outweigh the risks.

Information about how to receive the Pfizer COVID-19 vaccine will be available shortly.

Does this mean I won’t be able to get vaccinated?

We are still aiming to vaccinate as many people in Australia as possible to protect us all from COVID-19.

SA Health and the Australian Government are working through the implications of the updated advice from ATAGI for the vaccine rollout program as an urgent priority, including how to ensure people who now need to have the Pfizer vaccine can receive it in a timely manner.

The vaccine rollout plan may be amended or delayed, but you will still be offered a vaccine as soon as possible.

Why is the advice different to other countries?

Each country’s advice has been informed by the local risk for COVID-19, how much of the population has already been vaccinated and in what age groups, and whether they have an alternative supply of vaccines.

Australia currently has very low or no community transmission of COVID-19, but this could change. The risk of serious disease and death in Australia remains, even as border controls and other measures continue.

The risk-versus-benefit assessment for the use of AstraZeneca COVID-19 vaccine is different for Australia compared to other countries, such as those with widespread transmission. This includes countries in our region such as those currently experiencing very serious outbreaks of COVID-19, such as Timor Leste, Papua New Guinea and others.

Who can I speak to if I have concerns?

If you’d like to speak to someone, you can call National Coronavirus Helpline 1800 020 080, your GP or your vaccine provider if you’ve already been vaccinated or have an appointment to be vaccinated.