A Phase 1/2 Dose-Ranging Safety and Immunogenicity Study of mRNA-Based Candidate Pandemic Influenza Vaccines in Healthy Adults
Year: 2026
Type: article
Study design: Clinical Trial
Abstract: BACKGROUND: Influenza A viruses pose a persistent pandemic threat. We report safety, reactogenicity, and immunogenicity findings for mRNA-1018 pandemic influenza vaccine candidates from a phase 1/2 study in healthy adults. METHODS: In part A, participants were randomized to receive 1 of 4 mRNA-1018 candidates at 1 of 3 dose levels across 2 influenza A groups: (1) H5N8/H5-only or (2) H7N9/H7-only. Part B participants were randomized to receive H5-only-CG. The primary objectives were to evaluate the safety and reactogenicity. The secondary objectives included evaluation of humoral immunogenicity through day 205 by hemagglutination inhibition (HAI), neuraminidase inhibition, and microneutralization assays. RESULTS: Parts A and B comprised 1195 and 304 dosed participants, respectively. Overall, solicited local adverse reactions (ARs) within 7 days of vaccination occurred in 76.8% of participants across vaccine candidates and dose levels, most commonly injection-site pain. Solicited systemic ARs were reported in 62.8% of participants, most frequently fatigue and headache. Postvaccination immune responses, assessed absolutely, by HAI titers and dynamically, by seroconversion rates, tended to increase with vaccine dose. H5-based candidates induced stronger strain-specific HAI. CONCLUSIONS: Vaccine candidates were sufficiently well tolerated and immunogenic. Further development of mRNA pandemic influenza vaccines is warranted.Clinical Trials Registration. NCT05972174.
Source: Clinical Infectious Diseases
DOI: 10.1093/cid/ciag278
Authors: Catherine A Cosgrove, Andrei Avanesov, Dondi Rust, Seun Osibajo, Kingston Kang, Brett Leav, the ODYSSEY Study Group, Paul Heath, Saul Faust, Marta Boffito, Christopher Duncan, Fiona Burns, Amardeep Heer, Philip Kalra, Rajeka Lazarus, Adrian Palfreeman, Tommy Rampling, Anil Shenoy, Anna Goodman, Kamran Hussain, Orod Osanlou, Christopher Green, Jeremy Turner, Andrew Freedman, Rebecca Sutherland, David Fried, Rebecca Rivard, Nelia Sanchez-Crespo, Carlos Fierro, Paul Bradley, Lisa Holloway, Earl F Martin, Katie Ann Julien, Jay Meyer
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,763
OpenAlex ID: W7155644777