I have served on or chaired two dozen data safety monitoring boards for randomized trials of novel experimental drugs or devices. I can tell you firsthand that for COVID-19 vaccines, a 30-day regulatory window after injection is fair game for attribution of health events to the product when the adverse events of interest are known to be caused by the mRNA-induced Wuhan Spike protein.
Jabagi et al., New England Journal of Medicine, reported from the French National Health Data System linked to the national COVID-19 vaccination database disclosing cardiovascular events after mRNA BA4/BA5 bivalent boosters. All persons who were 50 years of age or older and who had received a booster dose between Oct. 6 and Nov. 9, 2022, were included in the study….