ATAGI notes that the European Medicines Agency (EMA) have completed a preliminary review on 18 March 2021 of reports of thrombotic (clotting) events following AstraZeneca COVID-19 vaccine. They have concluded that the benefits of vaccination using AstraZeneca COVID-19 vaccine continue to outweigh any risk of side effects.
The EMA review has found that the AstraZeneca vaccine is not associated with an increase in the overall risk of blood clots.
Reports of a rare syndrome of blood clots in conjunction with low platelets, or of clots in blood vessels in the brain were also examined. These are conditions which can occur naturally in the absence of vaccination.
Around 20 million people in Europe have received the AstraZeneca vaccine. There have been 18 reports of people who had clots in blood vessels which drain the brain (also called cerebral venous sinus thrombosis or CVST), and 7 reports of people who had blood clots in multiple vessels in the body (also called disseminated intravascular coagulation or DIC). It has not yet been confirmed whether the vaccine caused these events, and ongoing investigation is needed.
ATAGI considers the benefits of vaccination in protecting people in Australia from COVID-19 outweigh the rare potential risk of these rare blood clotting events, and supports the continued rollout of the AstraZeneca vaccine in Australia.
There are no changes to the ATAGI clinical guidance on the use of AstraZeneca at this time.
The only contraindications to vaccination are a history of anaphylaxis to a previous dose of the vaccine, or a component within the vaccine. The preliminary EMA analysis noted that these rare occurrences were mostly in younger women. However, due to the rarity of cases and absence of appropriate comparative data, and the lack of a clear causal link with the vaccine, it did not identify individual patient risk factors or specific population/s for whom the vaccine is not warranted or recommended.
ATAGI will continue to monitor any data on the use of all COVID-19 vaccines, including the AstraZeneca and Pfizer COVID-19 vaccines that emerges globally and data from Australian program.
ATAGI encourages health care providers and the public to report any unexpected or serious adverse events, including thrombotic disorders, occurring following any COVID-19 vaccines.
Read the statement from the Therapeutic Goods Administration (TGA).