Safety and durability of influenza and SARS-CoV-2 antibody responses through 6 months after a single dose of mRNA-1083, a multicomponent influenza and COVID-19 vaccine, in adults ≥50 years.

Clinical Snapshot

Key Findings

• P Value: Not reported in abstract

• Effect Size: HAI titers comparable to or higher than comparators; SARS-CoV-2 nAb responses higher than comparators

• Primary Outcome: Noninferiority of mRNA-1083 versus comparators for influenza HAI responses and SARS-CoV-2 neutralizing antibody responses at Day 29

• Nnt Or Sensitivity: Not applicable - immunogenicity study rather than clinical efficacy

• Confidence Interval: Not reported in abstract

Clinical Application

High feasibility if approved - single injection replacing two separate vaccines, potentially improving compliance Would require TGA approval; could be considered for PBS listing if cost-effective compared to separate vaccines; aligns with ATAGI recommendations for annual influenza and COVID-19 vaccination in older adults Adults aged 50 years and older requiring seasonal influenza and COVID-19 vaccination

Abstract

Seasonal influenza and SARS-CoV-2 continue to contribute substantially to global morbidity and mortality. mRNA-1083 is an investigational multicomponent mRNA vaccine targeting seasonal influenza and SARS-CoV-2. In this phase 3, observer-blind, active-controlled trial (NCT06097273), adults (aged ≥50 y) were randomly assigned (1:1) to receive mRNA-1083 (40 µg; plus placebo) or age-appropriate licensed comparator vaccines for influenza and COVID-19. Two substudies were included: Cohort A (≥65 y) and Cohort B (50-64 y). Primary objectives were to demonstrate noninferiority of mRNA-1083 versus comparators for influenza hemagglutination inhibition (HAI) responses and SARS-CoV-2 neutralizing antibody (nAb; PsVNA) responses at Day 29 after vaccination and to evaluate safety and reactogenicity of study vaccines. Here, we report safety, reactogenicity, and immunogenicity of mRNA-1083 through Day 181 in adults aged ≥50 y. mRNA-1083 induced HAI titers against all vaccine-matched influenza strains that were maintained through 6 months and were generally comparable to, or higher than, comparator responses. SARS-CoV-2 nAb responses remained higher for mRNA-1083 than comparators through 6 months. Reactogenicity was predominantly grade 1-2 in severity, and vaccination-related unsolicited adverse events were similar between groups. No serious adverse events or deaths related to vaccination were reported through 6 months. In adults aged ≥50 y, mRNA-1083 elicited durable influenza and SARS-CoV-2 humoral immune responses with an acceptable safety profile through 6 months. These findings support the use of mRNA-1083 as a multicomponent vaccine.ClinicalTrials.gov identifier: NCT06097273 (https://clinicaltrials.gov/study/NCT06097273).

References

1. 1.Kostanyan, L., Wu, I., Sinkiewicz, M., Cardona, J., Johnson, K., & Das, R. (2026). Safety and durability of influenza and SARS-CoV-2 antibody responses through 6 months after a single dose of mRNA-1083, a multicomponent influenza and COVID-19 vaccine, in adults ≥50 years. Human Vaccines & Immunotherapeutics. https://doi.org/10.1080/21645515.2026.2675021