The US Food and Drug Administration’s emergency use authorization of the Pfizer Inc./BioNTech SE and Moderna, Inc. COVID-19 vaccine boosters for use in everyone ages 18 years and older was not based on new clinical efficacy or immunogenicity data. Instead, the authorizations relied on the same immune response data that supported the vaccines’ previous EUAs for booster doses in certain high-risk populations.
However, the FDA also took into account additional real-world data that have become available on the recently increasing number of...