Respiratory syncytial virus (RSV) is the most common cause of hospitalization among U.S. infants, with those aged 0-2 months at greatest risk. Every year in the U.S., RSV causes 58,000-80,000 hospitalizations and 100-300 deaths in children less than 5 years of age. Worldwide, RSV causes 3.6 million hospitalizations and 100,000 deaths every year. Because children less than 2 months of age are at greatest risk, strategies to prevent the disease have been based on passive immunity acquired either through maternal vaccination during weeks 32-36 of pregnancy or administration of a long-acting monoclonal antibody (nirsevimab) for all infants 0-7 months of age and infants 8-19 months of age at greatest risk.
Recently, researchers at the Centers for Disease Control and Prevention (CDC) published the results of a study examining the impact of maternal RSV vaccination and nirsevimab, both of which were available for the 2024-2025 RSV season (Patton M, Moline HL, Whitaker M, et al. 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. MMWR Morb Mortal Wkly Rep. 2025 May 8;74:273-281).
Hospitalization rates in children during the 2024-2025 RSV season were compared to rates during the 2018-2020 RSV seasons. Comparing data from two different surveillance systems (RSV-Associated Hospitalization Surveillance Network (RSV-NET) and New Vaccine Surveillance Network (NVSN)), the authors found that maternal RSV vaccination and nirsevimab decreased hospitalization rates by 43% and 28%, respectively. The largest rate reduction was in children 0-2 months of age (52% and 45%).
The authors concluded that “these findings support Advisory Committee on Immunization Practices’ recommendations for maternal vaccination or nirsevimab to protect against severe RSV disease in infants and highlight the importance of implementing the recommendations to protect infants as early in the RSV season as possible, before peak transmission ...” (abstract).
Contributed by: Paul A. Offit, MD
Respiratory syncytial virus (RSV) is the most common cause of hospitalization among U.S. infants, with those aged 0-2 months at greatest risk. Every year in the U.S., RSV causes 58,000-80,000 hospitalizations and 100-300 deaths in children less than 5 years of age. Worldwide, RSV causes 3.6 million hospitalizations and 100,000 deaths every year. Because children less than 2 months of age are at greatest risk, strategies to prevent the disease have been based on passive immunity acquired either through maternal vaccination during weeks 32-36 of pregnancy or administration of a long-acting monoclonal antibody (nirsevimab) for all infants 0-7 months of age and infants 8-19 months of age at greatest risk.
Recently, researchers at the Centers for Disease Control and Prevention (CDC) published the results of a study examining the impact of maternal RSV vaccination and nirsevimab, both of which were available for the 2024-2025 RSV season (Patton M, Moline HL, Whitaker M, et al. 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. MMWR Morb Mortal Wkly Rep. 2025 May 8;74:273-281).
Hospitalization rates in children during the 2024-2025 RSV season were compared to rates during the 2018-2020 RSV seasons. Comparing data from two different surveillance systems (RSV-Associated Hospitalization Surveillance Network (RSV-NET) and New Vaccine Surveillance Network (NVSN)), the authors found that maternal RSV vaccination and nirsevimab decreased hospitalization rates by 43% and 28%, respectively. The largest rate reduction was in children 0-2 months of age (52% and 45%).
The authors concluded that “these findings support Advisory Committee on Immunization Practices’ recommendations for maternal vaccination or nirsevimab to protect against severe RSV disease in infants and highlight the importance of implementing the recommendations to protect infants as early in the RSV season as possible, before peak transmission ...” (abstract).
Contributed by: Paul A. Offit, MD