Efficacy and Safety of an mRNA-Based RSV PreF Vaccine in Older Adults
In RCT (n=35,541), single dose mRNA-1345 vaccine resulted in lower incidence of RSV-linked lower respiratory tract disease (RTD) & RSV-linked acute RD vs placebo in adults ≥60 years (vaccine efficacy 83.7% & 82.4% against RSV disease with ≥2 & ≥3 signs/symptoms, respectively).
Source:
New England Journal of Medicine
SPS commentary:
Participants in the mRNA-1345 group had a higher incidence than those in the placebo group of solicited local adverse reactions (58.7% vs. 16.2%) and of systemic adverse reactions (47.7% vs. 32.9%).
An editorial notes that the trial had limited follow-up and assessed efficacy to a median of only 112 days (range, 1 to 379), but the trial will continue to evaluate the immune response up to 24 months after vaccination. It adds that an important consideration will be how much protection an mRNA vaccine provides during subsequent RSV seasons and whether subsequent boosting will be appropriate. It suggests such questions about duration of immunity, along with reactogenicity and cold-chain considerations, remain important areas for further evaluation in the implementation of mRNA vaccines.