Efficacy of Approved Versus Unapproved Vaccines for Severe Acute Respiratory Syndrome Coronavirus 2 Infection in Randomized Blinded Clinical Trials.

This meta-analysis of 21 RCTs in 390 459 participants showed no significant difference in efficacy between the FDA/EMA-approved and -unapproved vaccines for symptomatic or severe infection. Differences in study design, endpoint definitions, variants, and infection prevalence may have influenced results. New patent-free vaccines could lower costs of worldwide SARS-CoV-2 vaccination campaigns significantly.