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Updated: May 5, 2026
An In vitro Model to Study Immune Responses of Human Peripheral Blood Mononuclear Cells to Human Respiratory Syncytial Virus Infection
Published on: December 10, 2013
Humoral Immunogenicity of mRNA-1345 RSV Vaccine in Older Adults
Jaya Goswami1, Abdullah H Baqui2, Pablo A Doreski3
1Infectious Disease, Research and Development, Moderna, Inc., Cambridge, Massachusetts.
Background:
The mRNA-1345 vaccine demonstrated efficacy against respiratory syncytial virus (RSV) disease with acceptable safety in adults aged ≥60 years in the ConquerRSV trial. Here, humoral immunogenicity results from the trial are presented.
Methods:
This phase 2/3 trial randomly assigned adults (≥60 years) to mRNA-1345 50-µg encoding prefusion F (preF) glycoprotein (n = 17 793) vaccine or placebo (n = 17 748). RSV-A and RSV-B neutralizing antibody (nAb) and preF binding antibody (bAb) levels at baseline and day 29 postvaccination were assessed in a per-protocol immunogenicity subset (PPIS; mRNA-1345, n = 1515; placebo, n = 333).
Results:
Day 29 nAb geometric mean titers (GMTs) increased 8.4-fold against RSV-A and 5.1-fold against RSV-B from baseline. Seroresponses (4-fold rise from baseline) in the mRNA-1345 groups were 74.2% and 56.5% for RSV-A and RSV-B, respectively. Baseline GMTs were lower among participants who met the seroresponse criteria than those who did not. mRNA-1345 induced preF bAbs at day 29, with a pattern similar to nAbs. Day 29 antibody responses across demographic and risk subgroups were generally consistent with the overall PPIS.
Conclusions:
mRNA-1345 enhanced RSV-A and RSV-B nAbs and preF bAbs in adults (≥60 years) across various subgroups, including those at risk for severe disease, consistent with its demonstrated efficacy in the prevention of RSV disease.
Clinical Trials Registration:
NCT05127434.
