Safety and Immunogenicity of a Recombinant Adenovirus Type-5–Vectored Coronavirus Disease 2019 (COVID-19) Vaccine With a Homologous Prime-Boost Regimen in Healthy Participants Aged ≥6 Years: A Randomized, Double-Blind, Placebo-Controlled, Phase 2b Trial

BackgroundWe assessed the safety and immunogenicity of a recombinant adenovirus type-5 (Ad5)–vectored coronavirus disease 2019 (COVID-19) vaccine with homologous prime-boost regimens in healthy participants aged ≥6 years.