The Australian government has withdrawn approval of the Vaxzevria AstraZeneca COVID-19 vaccine due to its rare but serious side effect of thrombosis with thrombocytopenia (TTS), characterized by blood clots in combination with low blood platelets. According to the federal health department, the vaccine developed by Oxford University is no longer available as an approved vaccine as of March 20, 2023. The Therapeutic Goods Administration has reported eight TTS-related deaths in Australia following the AstraZeneca vaccine. The vaccine was available for use as a first and booster dose from February 2021 and February 2022 respectively, but from October 2021, it was only available upon request, in favor of newer mRNA vaccines such as Pfizer, Moderna, and Novavax.
The AstraZeneca vaccine was initially deemed “highly safe and effective,” but as research suggested unsatisfactory results against new variants and its causal link with rare but severe incidents, including low platelet counts, blood clots, and hemorrhages, countries began to suspend its use. South Africa was the first to cancel its rollout of the AstraZeneca vaccine after data revealed its inadequacy in providing protection against infection among young people. Norway, Denmark, and Iceland also suspended the vaccine entirely until more evidence on its potential side effects was available. Other countries, including Romania, Ireland, Sweden, France, Germany, Italy, and Spain, applied temporary suspensions to batches.
The European Medicines Agency’s safety committee has listed unusual blood clots with low blood platelets as a very rare side effect of the AstraZeneca vaccine. After an update on side effects, Norway and Denmark suspended the vaccine, with the Norwegian government deciding to completely stop administering the vaccine from May 12. Australia’s phase-out of the vaccine was due to the availability of newer options, and it was not a decision based on safety. The AstraZeneca COVID-19 vaccine remains provisionally approved by the TGA. However, the sponsor made a commercial decision with respect to the supply of AstraZeneca vaccine in Australia.