mRNA-1083 induced higher immune responses than recommended standard-care influenza and COVID-19 vaccines
By Elana Gotkine HealthDay Reporter
FRIDAY, May 9, 2025 (HealthDay News) — mRNA-1083 vaccine is noninferior and induces higher immune responses than recommended influenza and COVID-19 vaccines against several influenza strains and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), according to a study published online May 7 in the Journal of the American Medical Association.
Amanda K. Rudman Spergel, M.D., from Moderna Inc. in Cambridge, Massachusetts, and colleagues examined the immunogenicity and safety of an investigational mRNA-1083 vaccine against seasonal influenza and SARS-CoV-2 in adults aged 50 years and older in a trial conducted across 146 U.S. sites. Adults aged 65 years and older (4,017 participants) and 50 to 64 years (3,998 participants) were randomly assigned to receive mRNA-1083 plus placebo or coadministered licensed quadrivalent seasonal influenza (65 years and older: high-dose quadrivalent inactivated influenza vaccine [HD-IIV4]; 50 to 64 years: standard-dose IIV4 [SD-IIV4]) and COVID-19 (mRNA-1273) vaccines.
The researchers found that based on the lower bound of the 97.5 percent confidence interval of the geometric mean ratio greater than 0.667 and lower bound of the 97.5 percent confidence interval of the seroconversion/seroresponse rate difference greater than −10 percent, noninferior immunogenicity of mRNA-1083 was demonstrated against all vaccine-matched influenza and SARS-CoV-2 strains. Higher immune responses were elicited by mRNA-1083 than SD-IIV4 (50 to 64 years) for all four influenza strains and HD-IIV4 (65 years and older) for three influenza strains, and against SARS-CoV-2 (all ages). Relative to comparators, solicited adverse reactions were numerically higher in frequency and severity after mRNA-1083 vaccination than comparators in both age cohorts.
“This pivotal phase 3 study demonstrated the noninferiority of a single mRNA-1083 dose in adults 50 years and older,” the authors write.
Several authors disclosed ties to biopharmaceutical companies, including Moderna, which is developing the mRNA-1083 vaccine and funded the study.
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