Claims of inadequate testing on the updated COVID-19 vaccine

Numerous social media users have raised concerns regarding what they claim is insufficient testing for the recently updated COVID-19 vaccine. Tweets allege that Pfizer’s updated COVID-19 vaccine was tested on just 10 mice before approval. These posts misuse a COVID-19 vaccine study involving 44 rats, not four. The study was published in 2021, before the most recently updated vaccine was developed. These claims also ignore the vigorous testing and monitoring of the COVID-19 vaccine over the past three years.

Risk level: High

Recommendation: The narratives above show ongoing mistrust in the safety of mRNA COVID-19 vaccines, including the newly updated vaccines. The popularity of these false claims as updated vaccines are rolled out elevates the risk, especially because similar claims last fall may have contributed to low uptake of COVID-19 boosters.Talking points may emphasize that the COVID-19 vaccine has been monitored for over three years and has been deemed safe. Minor changes to the vaccines, like those in the updated COVID-19 vaccines from Pfizer and Moderna, do not impact its safety.