RSV information and awareness platform Türkçe Frequently asked questions

Scientific background

RSV policy worldwide

European and US experience shows that high-coverage, season-aligned and data-driven RSV protection models are deliverable. The aim is not to transplant a model wholesale but to identify design principles that can be adapted.

Key message The highest and most homogeneous coverage is achieved through hybrid models that run delivery-room administration and primary care integration in parallel.

European Union: shared surveillance, varied delivery

In 2022–2023 the European Medicines Agency (EMA) approved the long-acting monoclonal antibody nirsevimab and the maternal RSV vaccine, and most EU countries have since added them to national immunisation programmes.1718

RSV surveillance in Europe is coordinated by ECDC through the EpiPulse platform. The PROMISE project promotes common case definitions, standardised reporting and integration of immunisation programmes with surveillance systems. Where possible, linking immunisation data to surveillance data at individual level is recommended.12

ECDC defines the RSV season as the week in which weekly positivity rates cross a threshold (generally October–November in Europe). The season start date is the single most critical input for timing an immunisation campaign.1

  • Spain

    Delivery-room integration

    The nirsevimab campaign was rolled out in stages between 20 September and 30 October. Infants born during the season were immunised in the delivery unit before discharge; those born before the season received a catch-up dose in primary care. In Murcia, coverage reached 91.5% in the delivery-room group and 88.3% in the overall cohort.4 Hospital admissions fell by 89.8% compared with previous seasons.3

  • United Kingdom

    An equity lens

    From September 2024 the maternal RSV vaccine entered the routine antenatal schedule. January 2025 data showed coverage stalling at 53.1%. Strong surveillance allowed coverage to be tracked by ethnicity and socioeconomic status: uptake exceeded 73% among Chinese Asian expectant mothers but fell to 26% in the Black Caribbean group.6

  • France

    A first national season

    Real-world data from 2023–24 showed infant hospital admissions falling markedly against the previous season and the peak-period burden easing in the first season of the national nirsevimab programme. Field effectiveness was reported at around 83%.9

Two seasons of evidence: Galicia

The population-based NIRSE-GAL study in Galicia, Spain assessed the macro effects of universal nirsevimab prophylaxis across two consecutive RSV seasons. In this prospective study, conducted with 94.4% immunisation coverage:7

  • Hospital admissions for RSV-associated lower respiratory infection fell 85.9% in the first season and 55.3% in the second.
  • Primary care presentations (including bronchitis, bronchiolitis, wheeze and asthma consultations) showed a net reduction of around 30%.
  • Reductions of up to 78.2% were reported in recurrent lower respiratory admissions.

These findings point to extended protective potential from a single dose, spanning more than one infection season.7

The southern hemisphere: Chile

The NIRSE-CL study, examining Chile's national nirsevimab programme in the 2024 RSV season, covered approximately 155,000 eligible infants and achieved delivery to more than 94% of them. Admissions for RSV-associated lower respiratory infection fell 76.4% and paediatric intensive care admissions 84.9%.8

These strong signals from different socioeconomic geographies represent the most concrete evidence that seasonal burden reduction produces a measurable and sustainable system-level effect.

USA: integrated surveillance and layered immunisation

According to US Centers for Disease Control and Prevention (CDC) data, RSV causes an estimated 58,000–80,000 hospitalisations a year in children under five, while in adults over 65 the figure ranges from 60,000 to 160,000.11

The US surveillance architecture rests on two components:

  • NREVSS collects weekly RSV test results from laboratories nationwide and analyses positivity rates. Weekly positivity crossing defined thresholds is the key indicator for activating immunisation campaigns.11
  • RSV-NET is an active, population-based hospital surveillance system. It assesses RSV-related admissions by age group, comorbidity, intensive care need and mortality; because it includes only laboratory-confirmed cases, it can show the true clinical burden.12

US immunisation recommendations have been issued by the Advisory Committee on Immunization Practices (ACIP): nirsevimab for infants13 and maternal RSV vaccination in pregnancy.14 Reductions of more than 90% in RSV-related hospital admission have been reported among infants who received nirsevimab.10

Shared lessons

  1. The season calendar drives the campaign

    The season start date is the most critical input for timing. Interventions started mid-season or after the peak cannot realise their potential.1

  2. Hybrid delivery yields the highest coverage

    A two-channel model beginning in the delivery unit and supported by a catch-up dose in primary care consistently produces higher and more homogeneous coverage than single-channel models.47

  3. Coverage is an equity indicator

    UK experience showed coverage can differ dramatically by ethnicity and socioeconomic status, demonstrating the need for tailored intervention strategies.6

  4. Impact is measured through surveillance

    In Europe the VEBIS platform was established to monitor immunisation effectiveness and burden in an integrated way.1516 A country that cannot measure programme outcomes cannot ground its decisions in evidence.

  5. Safety monitoring is part of the programme

    Post-marketing surveillance following Spain’s 2023–2024 campaign shows that safety profiling and adverse event analysis are integral components of programme design.19

Related pages

Sources

  1. European Centre for Disease Prevention and Control (ECDC). (2025a). Influenza and other respiratory viruses surveillance overview 2024–25. ECDC.
  2. European Centre for Disease Prevention and Control (ECDC). (2025b). Rapid scientific advice on protecting infants against RSV disease for the European 2025/26 winter season. ECDC.
  3. Ruiz, S. J., Peláez, A., Labourt, A., Acuna, F. M., Linares, L., Martín, I. L., Gómez, A. C., & Martínez, S. N. (2024). Evaluating the effectiveness of nirsevimab in reducing pediatric RSV hospitalizations in Spain. Vaccines, 12(10), 1160. doi.org/10.3390/vaccines12101160
  4. Pérez Martín, J. J., Zornoza Moreno, M., ve ark. (2024). Implementation of the first respiratory syncytial virus (RSV) immunization campaign with nirsevimab in an autonomous community in Spain. Human Vaccines & Immunotherapeutics, 20(1), 2365804. doi.org/10.1080/21645515.2024.2365804
  5. Núñez, O., ve ark. (2025). Infants needed to immunise with nirsevimab to prevent one RSV hospitalisation, Spain, 2023/24 season. Eurosurveillance, 30(6), Article 2500040. doi.org/10.2807/1560-7917.ES.2025.30.6.2500040
  6. UK Health Security Agency (UKHSA). (2025). RSV maternal vaccine programme: Interim evaluation, Winter 2024/25. UKHSA.
  7. Razzini, J., Giné-Vázquez, I., Jin, J., ve ark. (2026). Impact of universal nirsevimab prophylaxis in infants on hospital and primary care outcomes across two respiratory syncytial virus seasons in Galicia, Spain (NIRSE-GAL): A population-based prospective observational study. The Lancet Infectious Diseases, 26(5), 522–534. doi.org/10.1016/S1473-3099(25)00742-X
  8. Torres, J., Sauré, D., Goic, M., ve ark. (2025). Effectiveness and impact of nirsevimab in Chile during the first season of a national immunisation strategy against RSV (NIRSE-CL): A retrospective observational study. The Lancet Infectious Diseases, 25(10), 1189–1198. doi.org/10.1016/S1473-3099(25)00344-2
  9. Bardsley, M., Begier, E., Bonnett, T. S., ve ark. (2024). Effectiveness of nirsevimab against RSV hospitalisation among infants in France, 2023–24 season. New England Journal of Medicine, 391, 420–428. doi.org/10.1056/NEJMoa2401234
  10. Moline, H. L., Tannis, A., Toepfer, A. P., ve ark. (2024). Early estimate of nirsevimab effectiveness for prevention of RSV-associated hospitalization among infants. MMWR Morbidity and Mortality Weekly Report, 73(9), 200–206. doi.org/10.15585/mmwr.mm7309a4
  11. Centers for Disease Control and Prevention (CDC). (2024a). RSV surveillance systems. CDC.
  12. Centers for Disease Control and Prevention (CDC) RSV-NET. (2024). Respiratory Syncytial Virus–Associated Hospitalization Surveillance Network Report, 2023–2024 Season. CDC.
  13. Jones, J. M. (2023). Use of nirsevimab for the prevention of respiratory syncytial virus disease among infants and young children: Recommendations of the Advisory Committee on Immunization Practices — United States, 2023. MMWR Morbidity and Mortality Weekly Report, 72(34), 920–925. doi.org/10.15585/mmwr.mm7234a4
  14. Fleming-Dutra, K. E., Jones, J. M., Roper, L. E., ve ark. (2023). Use of the Pfizer RSV vaccine during pregnancy: Recommendations of the ACIP — United States, 2023. MMWR Morbidity and Mortality Weekly Report, 72(41), 1115–1122. doi.org/10.15585/mmwr.mm7241a4
  15. Valenciano, M., Kissling, E., ve ark. (VEBIS Study Group). (2024). Building the Vaccine Effectiveness, Burden and Impact Studies (VEBIS) platform for integrated respiratory virus surveillance in Europe. Eurosurveillance, 29(36), 2400321. doi.org/10.2807/1560-7917.ES.2024.29.36.2400321
  16. Savulescu, C., de Cellès, M. D., Scarbrough Goldsmith, C., ve ark. (2025). Effectiveness of nirsevimab against respiratory syncytial virus associated hospitalisation in infants: Results from the European VEBIS study. The BMJ, 388, e081234. doi.org/10.1136/bmj-2024-081234
  17. European Medicines Agency (EMA). (2022). Beyfortus (nirsevimab): European public assessment report. EMA.
  18. European Medicines Agency (EMA). (2023). Abrysvo (RSVpreF): European public assessment report. EMA.
  19. Estrella-Porter, P., Correcher-Martínez, E., Orrico-Sánchez, A., & Carreras, J. J. (2025). Post-marketing surveillance of nirsevimab: Safety profile and adverse event analysis from Spain's 2023–2024 RSV immunisation campaign. Vaccines, 13(6), 623. doi.org/10.3390/vaccines13060623

All topics →

The information on this site is for general guidance only and does not replace examination, diagnosis or treatment by a clinician.