RSV immunizations reduce severe disease

Respiratory syncytial virus immunizations reduced severe disease, especially hospitalization, in recommended groups.
*Systematic review of randomized and observational studies; Level 1 (OCEBM).

Citation

Senerth E, Sheikholeslamian SM, Babatunde I, et al. RSV Immunization Effectiveness and Safety for the 2026-2027 Respiratory Season. JAMA. Published online September 2, 2026. doi:10.1001/jama.2026.17871

Background

Respiratory syncytial virus causes major illness in infants, older adults, and people with weakened immune systems. This review updated evidence to guide prevention policy for the 2026-2027 season.

Patients

Older adults, pregnant people, infants, children, and immunocompromised persons. Excluded studies included preprints, abstracts only, non-English reports, and ineligible products or outcomes.

Intervention

United States-licensed respiratory syncytial virus vaccines and long-acting antibody products.

Control

Placebo, no immunization, or active comparator groups.

Outcome

Hospitalization, emergency or intensive care visits, laboratory-confirmed illness, and safety events.

Follow-up Period

Varied by study; key durability analyses followed patients up to 18 months.

Results

Population and intervention Key outcome Effect
Adults aged 60 years or older; vaccine Respiratory syncytial virus hospitalization 83.3% effectiveness (95% CI 42.9 to 96.9)
Older adults; vaccine durability Hospitalization, 12 to 18 months 48.5% effectiveness (95% CI 29.3 to 64.4)
Infants; nirsevimab antibody Respiratory syncytial virus hospitalization 63.6% to 93.0% effectiveness (95% CI 26.9 to 97.0)
Pregnancy vaccination Infant hospitalization 70.0% effectiveness in one observational study (95% CI 37.0 to 86.0)

CI: confidence interval. OCEBM: Oxford Centre for Evidence-Based Medicine.

No comparative pregnancy studies found increased preterm birth or other adverse pregnancy outcomes. No Guillain-Barré syndrome cases occurred in 3 randomized trials; 1 observational study suggested a possible short-term increase after vaccination.

Limitations

Many observational studies had serious or critical bias risk. Results were narratively summarized, not pooled. Rare safety events remain hard to measure precisely.

Funding

Philanthropic funding; no pharmaceutical funding reported.

Clinical Application

Follow current respiratory syncytial virus immunization recommendations for eligible patients; monitor future guidance on repeat dosing and rare safety signals.