Fig. 1: Enrollment and analysis populations in the trial.
a, Trial profile. Eligible participants were sequentially enrolled as two cohorts to receive single-second booster doses of 50 µg mRNA-1273 (enrolled during 18 February–8 March 2022) or 50 µg mRNA-1273.222 (enrolled during 10–23 August 2022). a379 participants were enrolled and received mRNA-1273; two participants had previously received the primary series but not a first booster dose and another participant had a major protocol deviation, and three were excluded from all analysis sets. Data cutoff dates were 23 September 2022 for mRNA-1273.222 at the day 29 interim analysis and 6 July 2022 for the within-study noncontemporaneous mRNA-1273 at the day 91 interim analysis6. b, Analysis populations. The full analysis set consisted of all participants who received study vaccine. The safety set consisted of all participants who received study vaccine and was used for all safety analyses except for solicited adverse reactions which were assessed in the solicited safety set. HIV, human immunodeficiency virus. aThe per-protocol set for immunogenicity consisted of all participants in the full analysis set who received the planned dose of study vaccination and had antibody data available at prebooster and day 29 and no major protocol deviations. bSeven participants in the mRNA-1273.222 and eight participants in the mRNA-1273 arm of the per-protocol immunogenicity set had missing prebooster SARS-CoV-2 information. cPrior SARS-CoV-2 infection based on positive RT–PCR and/or serology test at prebooster baseline. dThe per-protocol immunogenicity negative set (PPIS-negative) consists of participants in the per-protocol set for immunogenicity (PPIS) who have no serologic or virologic evidence of SARS-CoV-2 infection at prebooster baseline, that is, who are SARS-CoV-2 infection negative, based on both negative RT–PCR tests for SARS-CoV-2 and negative SARS-CoV-2 nucleocapsid antibody test, and is the primary analysis set for immunogenicity. A total of 379 participants received a second booster dose of 50 μg mRNA-1273; two participants had previously received the primary series but not a first booster dose, and another participant had a major protocol deviation. These three participants were excluded from all analysis sets.
