Vaccines are “Remarkably Safe,” According to Comprehensive Study

A comprehensive study of 20 years of vaccine data has found that vaccines, on the whole, are “remarkably safe.”

Despite the widespread use, there has been little examination of prevalence and significance of post-approval vaccine safety issues, according to the researchers.

They conducted a retrospective cohort study of data from initial and subsequent labels of all FDA-approved vaccines from between January 1, 1996 and December 31, 2015, the primary outcome of which was the prevalence and characteristics of post-approval safety-related label changes.

Overall, 57 FDA-approved vaccines were included in the study and 58 post-approval safety-related label changes associated with 25 vaccines occurred (49 warnings and precautions, 8 contraindications, 1 safety-related withdrawal). Among these changes, restrictions on vaccinated populations, such as pregnant women, immunocompromised patients, or pre-term infants, (n = 21) and allergies (n = 13) were the most common issues.

“Over a 20-year period, vaccines were found to be remarkably safe. A large proportion of safety issues were identified through existing post-marketing surveillance programs and were of limited clinical significance. These findings confirm the robustness of the vaccine approval system and post-marketing surveillance,” the researchers concluded.

—Michael Potts

Reference:

Tau N, Yahav D, Shepshelovich D. Postmarketing safety of vaccines approved by the U.S. Food and Drug Administration. Published online July 28, 2020. Ann Intern Med. doi:10.7326/M20-2726