Long‐term effects of Pfizer‐BioNTech COVID‐19 vaccinations on platelets

Abstract There is a global concern about the safety of COVID‐19 vaccines associated with platelet function. However, their long‐term effects on overall platelet activity remain poorly understood. Here we address this problem by image‐based single‐cell profiling and temporal monitoring of circulating platelet aggregates in the blood of healthy human subjects, before and after they received multiple Pfizer‐BioNTech (BNT162b2) vaccine doses over a time span of nearly 1 year. Results show no significant or persisting platelet aggregation trends following the vaccine doses, indicating that any effects of vaccinations on platelet turnover, platelet activation, platelet aggregation, and platelet‐leukocyte interaction was insignificant.