Information post AstraZeneca (Vaxzevria) vaccine

Thank you for taking an important step in moving toward a safer community

First of all, our team would like to thank you for taking the time and making the effort to come and receive the vaccine. We understand it’s a stressful experience, and appreciate your patience with us. You are also now on your way to being safer from contracting and transmitting COVID-19 and have reduced your risk of significant illness.

It takes about 2 weeks after your dose of vaccine to achieve maximal immunity from it, so it’s important to continue practicing COVID-19 safety to reduce your risk of exposure.

Below are some resources for information about your vaccination. This would all have been included in your consent form, but we realise it’s not always handy to dig that up. So please bookmark this page for future reference.

What to expect after vaccination

As with any vaccine, you may have some temporary side effects after receiving a COVID-19 vaccine.

Common side effects after the AstraZeneca (Vaxzevria) vaccine include:

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

Most side effects are mild and temporary, going away within 1-2 days. Less common side effects after Astrazeneca (Vaxzevria) include:

  • redness at the injection site
  • nausea
  • enlarged lymph nodes
  • feeling unwell
  • pain in limb
  • insomnia
  • itching at the injection site.

These side effects are usually mild and usually, go away within one or two days. Some recipients will experience more significant flu-like symptoms from this vaccination compared to other common vaccinations and may require time away from normal activities.

These symptoms may occur after either dose but are more common after the first dose. If you experience pain at the injection site or fever, headaches or body aches after vaccination, you can take paracetamol or ibuprofen. These help to reduce some of the above symptoms (you do not need to take paracetamol or ibuprofen before vaccination).

If there is swelling at the injection site, you can use a cold compress.

Rare side effects that have been reported after Astrazeneca (Vaxzevria) are:

  • severe allergic reaction (anaphylaxis).

Very rare side effects that have been reported after the Astrazeneca (Vaxzevria) are:

  • Thrombosis with thrombocytopenia (blood clotting, with a decreased number of platelets)

You should seek medical attention after vaccination if:

  • you think you are having an allergic reaction. Call 000 if you experience severe symptoms, such as difficulty breathing, wheezing, a fast heartbeat or collapsing
  • you are worried about a potential side effect or have new or unexpected symptoms
  • you have an expected side effect of the vaccine which has not gone away after a few days.
  • you are worried about thrombosis with thrombocytopenia (TTS)

Concerning signs or symptoms include:

  • Persistent headache which continues for at least 4 days after vaccination. Simple analgesia may alleviate headache initially, but it persists
  • Signs and symptoms of raised intracranial pressure or focal neurological deficits (weakness, slurred speech, loss of sensation) or seizures
  • Signs or symptoms suggestive of clotting in other anatomical locations (e.g. abdominal pain suggestive of thrombosis in the splanchnic circulation, or chest pain suggestive of pulmonary embolism)
  • Signs suggestive of clinically significant thrombocytopenia (low platelets), such as petechial rash or bleeding, or bruising not at the vaccine injection site that cannot be explained

For symptoms that are not urgent, you can see your regular healthcare provider (usually your GP). If we are your regular GP – you can make an appointment to see us (the way you usually would) – however, if you only came here for the vaccination please make an appointment with your regular GP as they will know your past history best.

Thrombosis with thrombocytopenia syndrome (TTS)

The AstraZeneca (Vaxzevria) vaccine appears to be associated with a rare side effect called thrombosis with thrombocytopenia syndrome (TTS).

What is TTS?

TTS involves blood clots (thrombosis) and low levels of blood platelets (thrombocytopenia), In Australia symptoms of TTS have occurred between 4 and 42 days post-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. 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.

How common is TTS?

Overall there is a very low chance of this side effect. But the rate is estimated to be higher in those under 60 years of age. Recent estimates of risk associated with first does of COVID-19 Vaccine AstraZeneca are listed in the table below:


Age Estimated risk of TTS per 100,000
AstraZeneca (Vaxzevria) vaccine doses (first dose)
<50 years 3.1
50-59 years 2.7
60-69 years 1.4
70-79 years 1.8
80+ years 1.9
*as of June 2021  

What symptoms does thrombosis with thrombocytopenia syndrome usually cause?

TTS is rare and occurs around 4-42 days after vaccination. Symptoms can include abdominal pain and/or severe headache that does not settle with pain relief. More information about TTS symptoms is in the patient information sheet on AstraZeneca (Vaxzevria) COVID-19 vaccine and thrombosis with thrombocytopenia syndrome. People should seek medical attention immediately if they experience these symptoms.

Are any groups more at risk of TTS?

The rate of TTS reported in Australia and overseas is higher in younger adults and it may be more common in women. However, cases have also been reported in men and in older people.

It is not yet clear if women are at higher risk. More women than men have been vaccinated in some countries as they are a large proportion of frontline healthcare workers and have been prioritised for vaccination.
Based on current information, we do not know if there are any pre-existing medical conditions that may contribute to developing TTS or make it worse if it occurs.

Thank you again

We know it’s a really tough and stressful time, and we’re glad you trusted us to help with this really important public health measure.

Green Square Health is a GP clinic also, and if you are looking for a regular doctor, we’re still accepting new patients (in a COVID-safe way).

If you want to learn more visit gshealth.com.au, or you can sign up for our regular newsletter for updates about general health, information about our services and any other important healthcare-related news. We promise we don’t send them out too frequently, and you can always opt-out.

We won’t be sending you any more emails as per this vaccine unless you had already signed up for our regular email. To sign up please visit www.gshealth.com.au/contact/