Immunogenicity of Ad26.COV2.S vaccine for COVID-19

(JAMA Network) In this phase 1 study, a single immunization with Ad26.COV2.S (Janssen/Johnson & Johnson) vaccine induced rapid binding and neutralization antibody responses as well as cellular immune responses. Two phase 3 clinical trials are currently underway to determine the efficacy of the Ad26.COV2.S vaccine.