Daily Respiratory Research Analysis
Across three complementary, real‑world studies, RSV prevention showed strong effectiveness and safety signals: maternal RSVpreF vaccination substantially reduced infant RSV hospitalizations; protein‑subunit vaccines in older adults were highly effective with a small, product‑specific GBS signal; and U.S. surveillance showed marked declines in infant RSV hospitalizations after program roll‑out. Together these data support rapid, season‑timed uptake of maternal and infant protection and informed p
Summary
Across three complementary, real‑world studies, RSV prevention showed strong effectiveness and safety signals: maternal RSVpreF vaccination substantially reduced infant RSV hospitalizations; protein‑subunit vaccines in older adults were highly effective with a small, product‑specific GBS signal; and U.S. surveillance showed marked declines in infant RSV hospitalizations after program roll‑out. Together these data support rapid, season‑timed uptake of maternal and infant protection and informed product selection in older adults.
Research Themes
- Real-world effectiveness of RSV immunization across age groups
- Vaccine safety signals and product-specific risk profiles
- Population-level impact of maternal and infant RSV prevention
Selected Articles
1. Real-world effectiveness of RSVpreF vaccination during pregnancy against RSV-associated lower respiratory tract disease leading to hospitalisation in infants during the 2024 RSV season in Argentina (BERNI study): a multicentre, retrospective, test-negative, case-control study.
This multicenter test‑negative case‑control study in Argentina found RSVpreF maternal vaccination reduced infant RSV‑LRTD hospitalizations by 78.6% through 3 months and 71.3% through 6 months, with 76.9% protection against severe LRTD. All RSV‑related in‑hospital deaths occurred in infants whose mothers were unvaccinated.
Impact: Provides the first national, real‑world effectiveness data post‑program implementation, directly informing maternal immunization policy and timing to protect infants during peak RSV circulation.
Clinical Implications: Prioritize timely maternal RSVpreF vaccination (32–36 weeks’ gestation per local policy) before RSV season to protect infants up to 6 months. Counseling should emphasize substantial hospitalization risk reduction and the observed absence of deaths among vaccinated dyads.
Key Findings
- Vaccine effectiveness against RSV-associated LRTD hospitalization: 78.6% (birth–3 months) and 71.3% (birth–6 months).
- Effectiveness against severe LRTD hospitalization through 6 months: 76.9%.
- All three RSV-related in-hospital infant deaths occurred in the unvaccinated maternal group.
Methodological Strengths
- Multicenter test-negative design minimizing care-seeking bias.
- Laboratory confirmation (PCR or IFA) for case definition with age-specific effectiveness estimates.
Limitations
- Retrospective design with potential residual confounding.
- Limited to a single season and one country; generalizability to other settings requires caution.
Future Directions: Evaluate durability across multiple seasons, effectiveness by gestational timing and coadministration, and combined population impact alongside infant monoclonal antibody programs.
2. Effectiveness and Safety of Respiratory Syncytial Virus Vaccine for US Adults Aged 60 Years or Older.
In >787k tested adults ≥60 years, RSV protein‑subunit vaccines showed 75% effectiveness against RSV‑associated ARI, mirroring trial results, with modest reductions in immunocompromised subgroups and the lowest VE in stem cell transplant recipients. Safety analyses of >4.7 million recipients detected no excess ITP, and a small but significant excess GBS risk for RSVPreF (not for RSVPreF+AS01).
Impact: Largest U.S. real‑world VE and safety assessment informs product selection, risk communication (GBS signal), and prioritization of high‑risk subgroups.
Clinical Implications: Offer RSV vaccination broadly to adults ≥60 and counsel that VE remains high across settings; consider slightly lower VE in immunocompromised, especially post‑transplant. Discuss small, product‑specific GBS risk when choosing between RSVPreF and RSVPreF+AS01.
Key Findings
- Overall VE against RSV-associated ARI: 75.1% (95% CI 73.6–76.4).
- VE modestly reduced in immunocompromised; lowest in stem cell transplant recipients (approx. 29–44%).
- Safety: no excess ITP; excess GBS per 1,000,000 doses for RSVPreF (~18.2) but not RSVPreF+AS01 (~5.2, not elevated).
Methodological Strengths
- Test-negative design paired with self-controlled case series for safety.
- Very large, nationally representative EHR dataset enabling subgroup analyses.
Limitations
- Observational design with potential misclassification and residual confounding.
- Product assignment not randomized; differing risk profiles may influence VE estimates.
Future Directions: Head‑to‑head comparative effectiveness, evaluation of durability across seasons, and mechanistic studies into product‑specific GBS associations.
3. Interim Evaluation of Respiratory Syncytial Virus Hospitalization Rates Among Infants and Young Children After Introduction of Respiratory Syncytial Virus Prevention Products - United States, October 2024-February 2025.
Using RSV‑NET and NVSN surveillance, infant (0–7 months) RSV hospitalization rates in 2024–25 were substantially lower than 2018–20 pooled rates, with 43% and 28% reductions, respectively, and the greatest declines in 0–2 month infants and peak months. Data support ACIP recommendations for maternal vaccination or nirsevimab early in the season and soon after birth.
Impact: Provides timely, population‑level evidence that the combined maternal and infant prevention strategy reduces infant RSV hospitalizations in the U.S., guiding implementation timing and coverage optimization.
Clinical Implications: Health systems should ensure maternal vaccination during late pregnancy and prompt birth‑hospital nirsevimab administration for eligible infants to maximize protection before peak RSV transmission.
Key Findings
- Infant (0–7 months) RSV hospitalization rates reduced by 43% (RSV‑NET) and 28% (NVSN) vs 2018–20.
- Largest reductions in 0–2 month infants: 52% (RSV‑NET) and 45% (NVSN).
- Greatest impact observed during peak months (Dec–Feb), supporting early‑season implementation.
Methodological Strengths
- Dual national surveillance systems with historical comparison.
- Consistent signal across two networks and age strata.
Limitations
- Ecological comparison without individual vaccination linkage.
- Potential differences in testing practices and health‑care utilization across seasons.
Future Directions: Link individual vaccination/antibody data to outcomes, assess contributions of each product, and model optimal program timing and coverage targets.