Notes from the Field: Expanding Birthing Hospital Enrollment in the Vaccines for Children Program to Increase Infant Immunization Against Respiratory Syncytial Virus - United States, October 2023-March 2025.

Respiratory syncytial virus (RSV), the leading cause of hospitalization among U.S. infants, results in 50,000-80,000 associated hospitalizations and 100-300 deaths among children aged <5 years each year (1). In 2023, the Advisory Committee on Immunization Practices (ACIP) recommended two options for preventing severe RSV in infants: maternal RSV vaccination during pregnancy (2) or administration of nirsevimab, a long-acting monoclonal antibody to infants (1). Nirsevimab is recommended for infants aged <8 months during their first RSV season (October-March in most of the United States); ideally, it should be administered during the birth hospitalization or within the first week of life. In September 2023, ACIP passed a resolution to add nirsevimab to the Vaccines for Children (VFC) Program, a public-private partnership that provides CDC-purchased vaccines to VFC-eligible children (those who are uninsured or underinsured, insured through Medicaid, or who are American Indian or Alaska Native) at no cost. Approximately one half (52.2%) of U.S. children aged 19-35 months are VFC-eligible, and among those, 93.4% are insured by Medicaid (3). Medicaid-insured infants have a higher incidence of severe RSV infection than do privately insured infants (4). Providers enrolled in the VFC program are able to administer nirsevimab at no cost to eligible children. Enrollment of birthing hospitals in VFC thus has the potential to expand infant immunization against RSV. This report describes enrollment of U.S. birthing hospitals (those with more than one birth during the previous year or at least one registered maternity bed) in the VFC program since the introduction of nirsevimab.