Efficacy Analysis
REGRESSION, SARS-COV-2 INFECTION
Participants who (1) had no evidence of prior SARS-CoV-2 infection at baseline or to at least 7 days after the second injection, (2) received both injections of assigned treatment, and (3) had no major protocol deviations were included in all protective efficacy analyses. Vaccine efficacy was defined as (1 − RR) × 100, where RR is the relative risk of end point incidence rates between the 2 treatment groups. The estimated RR and 2-sided 95% CI were derived using Poisson regression with robust error variance. All data analyses were performed using SAS, version 9.4 (SAS Institute Inc).