What Happened

On May 30, 2025, the World Health Organization (WHO) published its first-ever position paper on immunization products to protect infants against respiratory syncytial virus (RSV). This paper outlines recommendations for two types of immunization: a maternal vaccine and long-acting monoclonal antibodies, including nirsevimab and the newly authorized clesrovimab. However, the coverage status for clesrovimab remains unclear as healthcare systems adapt to the new guidelines and recommendations.

Why It Matters

RSV is a leading cause of severe respiratory infections in infants, responsible for approximately 3.6 million hospitalizations and 100,000 deaths annually among children under five globally. The majority of these deaths occur in low- and middle-income countries, where access to medical care is limited. The introduction of effective immunization products is crucial in addressing this public health issue. The WHO's recommendations aim to enhance protection for infants, particularly those at high risk due to preterm birth or underlying health conditions. The uncertainty surrounding clesrovimab's coverage could impact its accessibility and implementation in clinical practice, making it essential for healthcare providers to stay informed about these developments.

What Changed

  • WHO now recommends the maternal RSV vaccine (RSVpreF) for pregnant women in their third trimester to provide passive immunity to infants [1].
  • Nirsevimab is recommended for administration to infants at birth or just before the RSV season to enhance their immunity against RSV [2].
  • Clesrovimab has received market authorization but its coverage details are still under review, creating ambiguity for healthcare providers [3].
  • The WHO position paper emphasizes the urgent need for comprehensive immunization strategies to reduce RSV-related morbidity and mortality in infants [4].
  • The guidelines highlight the importance of monitoring immunization coverage and effectiveness as these new products are integrated into routine care [5].

What This Means for Your Practice

Pediatricians and primary care providers should familiarize themselves with the new WHO recommendations regarding RSV immunization. They need to assess which infants qualify for nirsevimab and stay updated on the status of clesrovimab coverage as it evolves. Clinicians should begin discussing the benefits of maternal vaccination with expectant mothers, particularly those in high-risk categories. Additionally, monitoring local immunization data will be crucial to ensure that infants receive adequate protection against RSV. As implementation progresses, how will healthcare systems address the gaps in coverage for clesrovimab, and what strategies will be put in place to ensure equitable access to these immunization products?

Sources and Further Reading

  • World Health Organization. WHO position paper on immunization to protect infants against respiratory syncytial virus disease, May 2025. URL: https://www.who.int/publications/i/item/who-wer-10022-193-218
  • World Health Organization. Immunization, Vaccines and Biologicals. URL: https://www.who.int/teams/immunization-vaccines-and-biologicals/diseases/respiratory-syncytial-virus-(rsv)
  • World Health Organization. WHO outlines recommendations to protect infants against RSV. URL: https://www.who.int/news/item/30-05-2025-who-outlines-recommendations-to-protect-infants-against-rsv-respiratory-syncytial-virus
  • World Health Organization. Respiratory syncytial virus (RSV) immunization products. URL: https://www.who.int/news-room/questions-and-answers/item/respiratory-syncytial-virus-(rsv)-immunization-products
  • Centers for Disease Control and Prevention. Nirsevimab Coverage (IIS), Children 0 to 19 months. URL: https://www.cdc.gov/rsvvaxview/data/nirsevimab-coverage-jurisdiction.html