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Published on: January 26, 2019
Efficacy and Safety of an mRNA-Based RSV PreF Vaccine in Older Adults
Eleanor Wilson1, Jaya Goswami1, Abdullah H Baqui1
1From Moderna, Cambridge, MA (E.W., J.G., R. Dhar, L.W., J.D., P.G., A.K., L.L., S.M., R.M., C.A.P., A.K.S., B.J.K., F.S., W.H., C.R., K.S., S.K.S., C.A.S., J.M.M., R. Das, G.L.C.); Johns Hopkins Bloomberg School of Public Health, Baltimore (A.H.B.); Fundación Respirar-Vaccine Research Division (P.A.D.) and Hospital Militar Central Cirujano Mayor Dr. Cosme Argerich (G.P.-M.) - both in Buenos Aires; International Center for Diarrheal Disease Research, Dhaka, Bangladesh (K.Z.); Clinical Site Partners, Winter Park, FL (J.M.); Translational and Clinical Research Institute, Newcastle University, and the National Institute for Health and Care Research Newcastle Clinical Research Facility, Newcastle upon Tyne Hospitals NHS Foundation Trust - both in Newcastle upon Tyne, United Kingdom (C.J.A.D.); Center Hospital of the National Center for Global Health and Medicine, Tokyo (M.U.); Rokotetutkimusklinikka, Järvenpää, and Finnish Vaccine Research, Tampere - both in Finland (M.R.); Vaccine Research-Foundation for the Promotion of Health and Biomedical Research of the Valencia Region (FISABIO) Public Health, Valencia, Spain (L.P.-B.); and the University of Rochester, Rochester, NY (A.R.F., E.E.W.).
Background:
Respiratory syncytial virus (RSV) can cause substantial morbidity and mortality among older adults. An mRNA-based RSV vaccine, mRNA-1345, encoding the stabilized RSV prefusion F glycoprotein, is under clinical investigation.
Methods:
In this ongoing, randomized, double-blind, placebo-controlled, phase 2-3 trial, we randomly assigned, in a 1:1 ratio, adults 60 years of age or older to receive one dose of mRNA-1345 (50 microg) or placebo. The two primary efficacy end points were the prevention of RSV-associated lower respiratory tract disease with at least two signs or symptoms and with at least three signs or symptoms. A key secondary efficacy end point was the prevention of RSV-associated acute respiratory disease. Safety was also assessed.
Results:
Overall, 35,541 participants were assigned to receive the mRNA-1345 vaccine (17,793 participants) or placebo (17,748). The median follow-up was 112 days (range, 1 to 379). The primary analyses were conducted when at least 50% of the anticipated cases of RSV-associated lower respiratory tract disease had occurred. Vaccine efficacy was 83.7% (95.88% confidence interval [CI], 66.0 to 92.2) against RSV-associated lower respiratory tract disease with at least two signs or symptoms and 82.4% (96.36% CI, 34.8 to 95.3) against the disease with at least three signs or symptoms. Vaccine efficacy was 68.4% (95% CI, 50.9 to 79.7) against RSV-associated acute respiratory disease. Protection was observed against both RSV subtypes (A and B) and was generally consistent across subgroups defined according to age and coexisting conditions. 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%); most reactions were mild to moderate in severity and were transient. Serious adverse events occurred in 2.8% of the participants in each trial group.
Conclusions:
A single dose of the mRNA-1345 vaccine resulted in no evident safety concerns and led to a lower incidence of RSV-associated lower respiratory tract disease and of RSV-associated acute respiratory disease than placebo among adults 60 years of age or older. (Funded by Moderna; ConquerRSV ClinicalTrials.gov number, NCT05127434.).
Insights
The mRNA-1345 vaccine significantly reduced respiratory syncytial virus (RSV) lower respiratory tract disease in adults over 60. This RSV vaccine showed good efficacy and safety in clinical trials.
Area of Science:
- Vaccinology
- Infectious Diseases
- Immunology
Background:
- Respiratory syncytial virus (RSV) poses a significant health risk, causing considerable illness and death in older adults.
- mRNA-1345 is an investigational mRNA vaccine targeting the stabilized prefusion F glycoprotein of RSV.
Purpose of the Study:
- To evaluate the efficacy and safety of the mRNA-1345 RSV vaccine in adults aged 60 years and older.
- To assess the vaccine's ability to prevent RSV-associated lower respiratory tract disease and acute respiratory disease.
Main Methods:
- A Phase 2-3 randomized, double-blind, placebo-controlled trial involving 35,541 participants aged 60+.
- Participants received a single 50 microg dose of mRNA-1345 or a placebo in a 1:1 ratio.
- Efficacy endpoints included prevention of RSV-associated lower respiratory tract disease (2 or 3+ symptoms) and acute respiratory disease; safety was also monitored.
Main Results:
- Vaccine efficacy was 83.7% against RSV-associated lower respiratory tract disease (≥2 symptoms) and 68.4% against RSV-associated acute respiratory disease.
- Protection was consistent across RSV subtypes (A and B) and various demographic subgroups.
- Mild to moderate local and systemic adverse reactions were more frequent in the vaccine group, but serious adverse events were similar between groups (2.8%).
Conclusions:
- A single dose of mRNA-1345 demonstrated a favorable safety profile in older adults.
- The mRNA-1345 vaccine effectively reduced the incidence of RSV-associated lower respiratory tract disease and acute respiratory disease compared to placebo.
