Moderna’s mRNA Vaccine Candidate Prevents RSV-Associated Disease in Older Adults

Moderna’s investigational mRNA vaccine met the primary endpoint for the prevention of RSV-associated lower respiratory tract disease.

Topline results were announced from a phase 3 study evaluating Moderna’s investigational mRNA vaccine candidate, mRNA-1345, for the prevention of respiratory syncytial virus-associated lower respiratory tract disease (RSV-LRTD) in older adults.

The double-blind, placebo-controlled ConquerRSV trial ( Identifier: NCT05127434) enrolled approximately 37,000 adults 60 years of age and older. Participants were randomly assigned to receive a single dose of mRNA-1345 or placebo. The primary endpoint was vaccine efficacy, defined as the prevention of the first episode of RSV-LRTD with 2 or more symptoms, or with 3 or more symptoms, from 14 days post vaccination through 12 months.

Results showed vaccine efficacy of 83.7% (95% CI, 66.1-92.2; P <.0001) against RSV-LRTD, defined by 2 or more symptoms. There were 64 cases of RSV-LRTD with 2 or more symptoms reported in the interim analysis; 55 of these cases occurred in the placebo group while 9 occurred in the mRNA-1345 group. 

Vaccine efficacy against RSV-LRTD with 3 or more symptoms was reported to be 82.4% (96.36% CI, 34.8-95.3; P =.0078). Among the 20 cases of RSV-LRTD with 3 or more symptoms, 17 cases were observed in the placebo group and 3 cases were observed in the mRNA-1345 group.

The most commonly reported adverse reactions were injection site pain, fatigue, headache, myalgia, and arthralgia. The vaccine candidate was generally found to be well tolerated; no safety concerns were identified.

Based on these results, the Company intends to submit for regulatory approval in the first half of 2023.

This article originally appeared on MPR


Moderna announces mRNA-1345, an investigational respiratory syncytial virus (RSV) vaccine, has met primary efficacy endpoints in phase 3 trial in older adults. News release. Moderna. Accessed January 18, 2023.