Daily Respiratory Research Analysis
Real-world effectiveness of two RSV prevention strategies in infancy was demonstrated: maternal RSVpreF vaccination substantially reduced RSV-associated hospitalizations, and infant nirsevimab provided high protection against RSV lower respiratory tract disease. A modeling study projected large preventable burdens of pneumococcal disease with next-generation conjugate vaccines, informing future immunization policy.
Summary
Real-world effectiveness of two RSV prevention strategies in infancy was demonstrated: maternal RSVpreF vaccination substantially reduced RSV-associated hospitalizations, and infant nirsevimab provided high protection against RSV lower respiratory tract disease. A modeling study projected large preventable burdens of pneumococcal disease with next-generation conjugate vaccines, informing future immunization policy.
Research Themes
- RSV prevention in infancy
- Maternal immunization effectiveness
- Pneumococcal vaccine policy modeling
Selected Articles
1. Bivalent prefusion F vaccination in pregnancy and respiratory syncytial virus hospitalisation in infants in the UK: results of a multicentre, test-negative, case-control study.
In a multicentre test-negative case-control study of 537 mother–infant pairs across 30 UK hospitals, maternal RSVpreF vaccination reduced RSV-associated infant hospitalizations by 58%, and by 72% when vaccination occurred >14 days before delivery. Effectiveness in real-world implementation mirrored trial efficacy during the first UK season.
Impact: Provides robust, early real-world effectiveness estimates for maternal RSV vaccination during its first UK season, directly informing policy and uptake strategies.
Clinical Implications: Maternal RSVpreF vaccination should be prioritized and timed to occur at least 14 days before delivery to maximize infant protection against RSV hospitalization. Findings support strong antenatal vaccine uptake campaigns.
Key Findings
- Adjusted vaccine effectiveness was 58% against RSV-associated infant hospitalization when given at any time before delivery.
- Effectiveness was 72% when maternal vaccination occurred more than 14 days before delivery.
- The study analyzed 391 RSV-positive cases and 146 RSV-negative controls from 30 UK hospitals in the first season of program implementation.
Methodological Strengths
- Multicentre test-negative case-control design with adjustment for key confounders
- Patient and public involvement informing protocol; real-world first-season evaluation
Limitations
- Moderate sample size may limit precision for subgroup analyses
- Potential residual confounding and misclassification inherent to test-negative designs
Future Directions: Assess durability of protection across seasons, effectiveness against severe outcomes (ICU, mortality), and equity of uptake; evaluate combined strategies with infant monoclonal antibodies.
2. Effectiveness of Nirsevimab Against RSV and RSV-Related Events in Infants.
Among 31,900 eligible US infants, nirsevimab was associated with 87.2% effectiveness against RSV LRTD and 98.0% effectiveness against hospitalized RSV LRTD during the 2023–2024 season; effectiveness against PCR-confirmed RSV was 71.0%. Immunized infants with breakthrough RSV had fewer medical encounters and lower odds of hospitalization.
Impact: Provides large real-world effectiveness evidence supporting widespread infant nirsevimab deployment, including reductions in healthcare utilization.
Clinical Implications: Health systems should ensure timely nirsevimab access for eligible infants before RSV season; data support reductions in RSV hospitalizations and resource use.
Key Findings
- Effectiveness against RSV LRTD was 87.2% (adjusted) and 98.0% against hospitalized RSV LRTD.
- Effectiveness against PCR-confirmed RSV infection was 71.0%.
- Immunized infants with RSV LRTD had fewer encounters (adjusted mean difference −0.86) and lower odds of hospitalization (OR 0.11) than non-immunized infants.
Methodological Strengths
- Very large integrated healthcare cohort with time-to-event modeling
- Conditioning on birth month and adjustment for key demographic covariates
Limitations
- Observational design with potential residual confounding and selection bias
- Single health system may limit generalizability to other settings
Future Directions: Assess duration of protection across seasons, effectiveness in preterm or comorbid infants, and comparative effectiveness versus maternal vaccination.
3. Pneumococcal Serotype Distribution and Coverage of Existing and Pipeline Pneumococcal Vaccines.
Using MCMC-based synthesis of surveillance and epidemiologic data, the study estimated that broader-valency PCVs (e.g., PCV31) would cover up to 68% of pediatric AOM and 87% of adult nonbacteremic pneumonia, with substantial preventable US burdens spanning 270,000–3.3 million outpatient ARIs, 2,000–17,000 pneumonia hospitalizations, and 3,000–14,000 IPD cases annually.
Impact: Provides comparative, policy-relevant estimates of preventable disease burden for existing and pipeline PCVs, informing future vaccine composition and implementation strategies.
Clinical Implications: Health authorities can use these estimates to prioritize PCV formulations and target age groups with the greatest projected impact, optimizing prevention of pneumococcal respiratory disease and IPD.
Key Findings
- In children, PCV31 serotypes accounted for 68% of pneumococcal acute otitis media; in adults, PCV31 covered 87% (83–90%) of nonbacteremic pneumonia.
- For IPD, 42–85% (pediatric) and 42–94% (adult) cases were due to PCV-targeted serotypes across products.
- Estimated annual preventable burdens included 270,000–3,300,000 outpatient ARIs, 2,000–17,000 pneumonia hospitalizations, and 3,000–14,000 IPD cases in the US.
Methodological Strengths
- Markov chain Monte Carlo approach integrating multiple surveillance and epidemiologic datasets
- Stratified estimates across conditions (AOM, sinusitis, nonbacteremic pneumonia, IPD) and age groups
Limitations
- Model-based estimates depend on assumptions about serotype attribution and vaccine effectiveness
- US-focused inputs may limit applicability to other regions with different serotype ecology
Future Directions: Validate projections with post-licensure effectiveness data for newer PCVs; assess cost-effectiveness and equity impacts of alternative vaccine schedules.