Misleading claims about AstraZeneca blood clot risk

Vaccine manufacturer AstraZeneca acknowledged in court documents from an ongoing lawsuit in the U.K. that the blood-clotting condition thrombocytopenia syndrome (TSS) is a rare risk associated with its COVID-19 vaccine. Vaccine opponents and some tabloid sites misleadingly framed this as a bombshell admission even though TTS has been known to be a rare risk of both the AstraZeneca and Johnson & Johnson COVID-19 vaccines since 2021. One post claims that conspiracy theorists were right to refer to the COVID-19 vaccines as a “clot shot.” 

Recommendation: Misleading claims about blood clot risks and COVID-19 vaccines attempt to undermine the public’s perception of the safety of COVID-19 vaccines. Ensuring that informational materials, including websites and any FAQ materials, include prebunking messaging explaining that COVID-19 vaccines are safe is recommended. If directly debunking false claims about COVID-19 vaccines and TTS, messaging may emphasize that TTS was first reported as a rare vaccine risk in early 2021, which resulted in some countries restricting the use of these vaccines in certain higher-risk populations since then. The risk of TTS is extremely low and linked to AstraZeneca and Johnson & Johnson vaccines. The COVID-19 vaccines that are available now were created by Pfizer, Moderna, and Novavax.