tetano
Editor, Senior Moderator
N Engl J Med
. 2026 May 7;394(18):1803-1813.
doi: 10.1056/NEJMoa2516491.
Efficacy and Safety of an mRNA Seasonal Influenza Vaccine in Adults
Isabel Leroux-Roels[SUP] 1 [/SUP], Grace Huang[SUP] 2 [/SUP], Murdo Ferguson[SUP] 3 [/SUP], Anita Kohli[SUP] 4 [/SUP], Rebecca Clark[SUP] 5 [/SUP], Markus Bickel[SUP] 6 [/SUP], Mieke Soens[SUP] 2 [/SUP], Evelyn Du[SUP] 2 [/SUP], Alicia Pucci[SUP] 2 [/SUP], Bryony Hicks[SUP] 7 [/SUP], Colbie Eschen[SUP] 2 [/SUP], Rituparna Das[SUP] 2 [/SUP], Eleanor Wilson[SUP] 2 [/SUP]; Fluent Trial Investigators
Collaborators, Affiliations
Background: Seasonal influenza causes substantial illness and death in adults 50 years of age or older, even with current vaccines. An investigational messenger RNA (mRNA)-based vaccine called mRNA-1010 encodes hemagglutinin glycoproteins from World Health Organization-recommended influenza strains.
Methods: In this phase 3, double-blind, active-controlled trial, we randomly assigned adults 50 years of age or older to receive trivalent mRNA-1010 (37.5 μg, which includes 12.5 μg of each strain) or a licensed standard-dose comparator. The primary efficacy end point was relative vaccine efficacy against reverse-transcriptase-polymerase-chain-reaction (RT-PCR)-confirmed, protocol-defined influenza-like illness caused by influenza A or B, from at least 14 days after vaccination through the end of the influenza season. Hypothesis testing was conducted hierarchically to assess noninferiority (lower boundary of the 95% confidence interval [CI], >-10%), superiority (lower boundary of the 95% CI, >0%), and a higher level of superiority (lower boundary of the 95% CI, >9.1%).
Results: A total of 40,703 participants received mRNA-1010 (20,350 participants) or the standard-dose comparator (20,353 participants); the median follow-up was 181 days (range, 1 to 227). RT-PCR-confirmed, protocol-defined influenza-like illness was observed in 411 of 20,179 recipients of mRNA-1010 (2.0%) and 557 of 20,124 recipients of the standard-dose comparator (2.8%), which corresponds to a relative vaccine efficacy of 26.6% (95% CI, 16.7 to 35.4), thereby meeting the criteria for noninferiority, superiority, and higher-level superiority. Solicited adverse reactions were more frequent with mRNA-1010 than with the standard-dose comparator (injection-site pain in 65.8% vs. 29.8%, fatigue in 45.1% vs. 20.3%, headache in 37.8% vs. 18.0%, and myalgia in 35.4% vs. 11.6%); most reactions were mild to moderate and transient. Serious adverse events were reported in 2.2% of the recipients of mRNA-1010 (with three events considered by the investigator to be vaccine-related) and in 1.9% of the recipients of the standard-dose comparator (with two events considered by the investigator to be vaccine-related).
Conclusions: In this trial, mRNA-1010 was superior to standard-dose licensed vaccines for prevention of RT-PCR-confirmed, protocol-defined influenza-like illness in adults 50 years of age or older. Solicited adverse reactions were more frequent with mRNA-1010. (Funded by Blackstone Life Sciences and Moderna; Fluent ClinicalTrials.gov number, NCT06602024.).
. 2026 May 7;394(18):1803-1813.
doi: 10.1056/NEJMoa2516491.
Efficacy and Safety of an mRNA Seasonal Influenza Vaccine in Adults
Isabel Leroux-Roels[SUP] 1 [/SUP], Grace Huang[SUP] 2 [/SUP], Murdo Ferguson[SUP] 3 [/SUP], Anita Kohli[SUP] 4 [/SUP], Rebecca Clark[SUP] 5 [/SUP], Markus Bickel[SUP] 6 [/SUP], Mieke Soens[SUP] 2 [/SUP], Evelyn Du[SUP] 2 [/SUP], Alicia Pucci[SUP] 2 [/SUP], Bryony Hicks[SUP] 7 [/SUP], Colbie Eschen[SUP] 2 [/SUP], Rituparna Das[SUP] 2 [/SUP], Eleanor Wilson[SUP] 2 [/SUP]; Fluent Trial Investigators
Collaborators, Affiliations
- PMID: 42090792
- DOI: 10.1056/NEJMoa2516491
Background: Seasonal influenza causes substantial illness and death in adults 50 years of age or older, even with current vaccines. An investigational messenger RNA (mRNA)-based vaccine called mRNA-1010 encodes hemagglutinin glycoproteins from World Health Organization-recommended influenza strains.
Methods: In this phase 3, double-blind, active-controlled trial, we randomly assigned adults 50 years of age or older to receive trivalent mRNA-1010 (37.5 μg, which includes 12.5 μg of each strain) or a licensed standard-dose comparator. The primary efficacy end point was relative vaccine efficacy against reverse-transcriptase-polymerase-chain-reaction (RT-PCR)-confirmed, protocol-defined influenza-like illness caused by influenza A or B, from at least 14 days after vaccination through the end of the influenza season. Hypothesis testing was conducted hierarchically to assess noninferiority (lower boundary of the 95% confidence interval [CI], >-10%), superiority (lower boundary of the 95% CI, >0%), and a higher level of superiority (lower boundary of the 95% CI, >9.1%).
Results: A total of 40,703 participants received mRNA-1010 (20,350 participants) or the standard-dose comparator (20,353 participants); the median follow-up was 181 days (range, 1 to 227). RT-PCR-confirmed, protocol-defined influenza-like illness was observed in 411 of 20,179 recipients of mRNA-1010 (2.0%) and 557 of 20,124 recipients of the standard-dose comparator (2.8%), which corresponds to a relative vaccine efficacy of 26.6% (95% CI, 16.7 to 35.4), thereby meeting the criteria for noninferiority, superiority, and higher-level superiority. Solicited adverse reactions were more frequent with mRNA-1010 than with the standard-dose comparator (injection-site pain in 65.8% vs. 29.8%, fatigue in 45.1% vs. 20.3%, headache in 37.8% vs. 18.0%, and myalgia in 35.4% vs. 11.6%); most reactions were mild to moderate and transient. Serious adverse events were reported in 2.2% of the recipients of mRNA-1010 (with three events considered by the investigator to be vaccine-related) and in 1.9% of the recipients of the standard-dose comparator (with two events considered by the investigator to be vaccine-related).
Conclusions: In this trial, mRNA-1010 was superior to standard-dose licensed vaccines for prevention of RT-PCR-confirmed, protocol-defined influenza-like illness in adults 50 years of age or older. Solicited adverse reactions were more frequent with mRNA-1010. (Funded by Blackstone Life Sciences and Moderna; Fluent ClinicalTrials.gov number, NCT06602024.).