RSVPreF3 reduces RSV hospitalizations

The immune-boosted RSVPreF3 vaccine was linked to far fewer RSV-related hospitalizations.
*Retrospective matched cohort study; Level 3 (OCEBM).

Citation

Singer D, Steffens A, La EM, et al. Real-world effectiveness of adjuvanted RSVPreF3 vaccination in the prevention of RSV-related hospitalization among US adults aged ≥60 years. Chest. 2026. doi:10.1016/j.chest.2026.07.5002

Background

Respiratory syncytial virus can cause serious lung illness in older adults, especially those with chronic medical conditions. This study tested whether vaccination worked in routine US care, not just in trials.

Patients

Adults aged ≥60 years in a large US insurance claims database. Exclusions included prior RSV vaccination, recent RSV diagnosis, missing key data, or less than 14 days of follow-up.

Intervention

One dose of adjuvanted RSVPreF3 vaccine.

Control

Matched adults without RSV vaccination.

Outcome

Primary outcome: RSV-related hospitalization. Secondary outcomes included severe hospitalization, emergency visits, and death during RSV-related hospitalization.

Follow-up Period

Median 5.6 months; maximum 9.7 months.

Results

The analysis included 520,440 vaccinated and 2,081,760 unvaccinated adults. Effectiveness remained significant in high-risk groups, including lung disease, heart disease, diabetes, kidney disease, and weakened immunity.

Outcome Vaccine effectiveness People vaccinated to prevent 1 event
RSV-related hospitalization (primary) 75.6% (69.8–80.2) About 2,004
RSV-related hospitalization or emergency visit 76.4% (72.2–79.9) About 1,140
Severe RSV-related hospitalization 79.1% (71.0–84.9) About 3,973
Death during RSV-related hospitalization 66.8% (14.6–87.1) About 67,100

RSVPreF3: respiratory syncytial virus prefusion F3 vaccine. Estimates used weighted matched groups. The control was no RSV vaccination, not another RSV vaccine.

Limitations

Claims data may misclassify vaccination, diagnoses, and medical conditions. RSV cases were not laboratory-confirmed. Residual differences in health behavior may remain; negative control outcomes suggested some possible bias. Findings may not apply to uninsured adults. Follow-up covered only one RSV season. Relative benefits were large, but absolute event rates were low.

Funding

Sponsored by GSK; employees and contractors involved, creating potential bias.

Clinical Application

Offer RSV vaccination to eligible older or high-risk adults; evidence supports hospitalization reduction but not multi-season durability.