Vaccines are remarkable safe, according to a new 20-year study that researchers say confirms the strength of the vaccine approval system and postmarketing surveillance in the United States.
In this retrospective cohort study, postmarketing safety modifications in U.S. Food and Drug Administration (FDA)–approved vaccine labels of all vaccines that were FDA-approved between 1 January 1996 and 31 December 2015, were analyzed.
Of the 57 vaccines, approved by the FDA, 93% were approved based on data from randomized controlled trials. Postapproval, safety-related label modifications occurred 58 times, including 49 warnings and precautions, 8 contraindications, and 1 safety-related withdrawal.
About 35% of safety issues that triggered label modifications was expansion of population restrictions.
“Over a 20-year period, vaccines were found to be remarkably safe. A large proportion of safety issues were identified through existing postmarketing surveillance programs and were of limited clinical significance. These findings confirm the robustness of the vaccine approval system and postmarketing surveillance,” the authors concluded.
Tau N, Yahav D, Shepshelovich D, et al Postmarketing safety of vaccines approved by the U.S. Food and Drug Administration. Ann Int Med. 2020; https://doi.org/10.7326/M20-2726.