biostudies-literatureUnknown231(1)Ananworanich JModerna, Inc<h4>Background</h4>Seasonal influenza remains a global public health concern. A messenger RNA (mRNA)-based quadrivalent seasonal influenza vaccine, mRNA-1010, was investigated in a first-in-human, phase 1/2 clinical trial conducted in 3 parts.<h4>Methods</h4>In parts 1 to 3 of this stratified observer-blind study, adults aged ≥18 years were randomly assigned to receive a single dose (6.25-200 µg) of mRNA-1010 or placebo (part 1) or an active comparator (Afluria; parts 2 and 3). Primary study objectives were assessment of safety, reactogenicity, and humoral immunogenicity of mRNA-1010, placebo (part 1), or active comparator (parts 2 and 3). Exploratory end points included assessment of cellular immunogenicity (part 1) and antigenic breadth against vaccine heterologous strains (A/H3N2; partsThe Journal of infectious diseasese113-e122https://www.ebi.ac.uk/biostudies/studies/S-EPMC11793046biostudies-literatureSafety and Immunogenicity of mRNA-1010, an Investigational Seasonal Influenza Vaccine, in Healthy Adults: Final Results From a Phase 1/2 Randomized Trial.PMC11793046Choi ACarmona LKuo HHAnanworanich JHenry CAvanesov ANachbagauer RParis RStadlbauer DLee ITSchaefers KEnsz DHuang WChen RPucci AMcGrath SfalseSafety and Immunogenicity of mRNA-1010, an Investigational Seasonal Influenza Vaccine, in Healthy Adults: Final Results From a Phase 1/2 Randomized Trial.<h4>Background</h4>Seasonal influenza remains a global public health concern. A messenger RNA (mRNA)-based quadrivalent seasonal influenza vaccine, mRNA-1010, was investigated in a first-in-human, phase 1/2 clinical trial conducted in 3 parts.<h4>Methods</h4>In parts 1 to 3 of this stratified observer-blind study, adults aged ≥18 years were randomly assigned to receive a single dose (6.25-200 µg) of mRNA-1010 or placebo (part 1) or an active comparator (Afluria; parts 2 and 3). Primary study objectives were assessment of safety, reactogenicity, and humoral immunogenicity of mRNA-1010, placebo (part 1), or active comparator (parts 2 and 3). Exploratory end points included assessment of cellular immunogenicity (part 1) and antigenic breadth against vaccine heterologous strains (A/H3N2; parts2025-01-01T00:00:00Z2025 Feb2026-06-01T10:32:01.461Z2026-04-08T11:32:00.277ZS-EPMC117930463893484510.1093/infdis/jiae329