Five COVID Shot Safety Signals Found Internationally

Risk of Myocarditis and other AESI > Risk of COVID Hospitalizations (Part 17)

A multi-country retrospective cohort study, published in Vaccine, that analyzed and compared the pre-COVID background and observed rates of 13 AESI using the Adverse Events of Special Interest Study Protocol, to analyze and compare data from 10 sites across 8 countries (n = 99 million), from December 2020 to August 2023 found that 5 AESI occurred frequently enough over the baseline rates in the general population that they exceed the threshold for prioritized vaccine safety signals. These 5 AESI, which exceeded an observed to expected event ratio at the lower bound (of the confidence interval) greater than 1.5 included Guillain-Barré syndrome following the first Astrazeneca dose (2.49), cerebral venous sinus thrombosis following the first Astrazeneca dose (3.23), Acute disseminated encephalomyelitis following the first Moderna dose (3.78), myocarditis following the first 3 Moderna and Pfizer doses (6.10), and pericarditis following the Moderna primary series (2.64) and booster and Astrazeneca booster (6.91) within 42 days of the last dose.