In court documents from an ongoing lawsuit in the U.K., vaccine manufacturer AstraZeneca acknowledged that the blood clotting condition thrombosis with thrombocytopenia syndrome (TTS) is a rare risk associated with its COVID-19 vaccine. This story has been misleadingly framed as a “bombshell admission” on social media despite TTS being a known rare risk of both the AstraZeneca and Johnson & Johnson COVID-19 vaccines since 2021. AstraZeneca recently withdrew the vaccine from the global market due to a decline in demand, a decision that some vaccine opponents falsely claim is because of the TTS risk.
The widespread misleading coverage of this story increases its risk. Debunking messaging may emphasize that TTS has been publicly known as a rare vaccine risk since early 2021. Messaging may also explain that the risk is extremely low and linked only to the non-mRNA-based COVID-19 vaccines, resulting in some countries restricting the use of these vaccines in certain higher-risk populations. AstraZeneca requested that its vaccines be withdrawn because, “As multiple variant Covid-19 vaccines have since been developed, there is a surplus of available updated vaccines. This has led to a decline in demand for Vaxzevria, which is no longer being manufactured or supplied.” The company withdrew the vaccine from the European market in March and suspended its use in Australia in 2022 for similar reasons. Unlike mRNA vaccines, AstraZeneca’s vaccine has never been updated for newer variants, making it outdated and ill-equipped to fight COVID-19 compared to other available vaccines.
