Statistical analyses
infection
EVENTS, INFECTION, INFLUENZA
This phase 1/2 study did not test any formal statistical hypotheses. Sample size (described in the Supplementary Methods) was considered sufficient to provide a descriptive summary of the safety and immunogenicity of different dose levels of mRNA-1010. All safety assessments except for solicited local and systemic ARs were assessed in the safety population, which included all randomized participants who received vaccination. Solicited ARs were assessed in all participants in the safety population who contributed any solicited AR data (solicited safety population). The number of events of unsolicited AEs, SAEs, AESIs, and MAAEs were summarized, while descriptive summary statistics were provided for all other safety analyses.Immunogenicity analyses were performed in the per-protocol population, which included all randomly assigned participants who received vaccination and complied with immunogenicity blood sampling timing to have baseline and ≥1 post-vaccination time point assessment, did not have influenza infection at baseline through Day 29 (as documented by polymerase chain reaction), and had no major protocol deviation that impacted the immune response. The geometric mean of specific antibody titers with corresponding 95% confidence intervals (CIs) at Day 29 and GMFRs of specific antibody titers with corresponding 95% CI at Day 29 over Day 1 (baseline) were calculated for each vaccination group; 95% CIs were calculated based on the 