A study published in The Lancet Infectious Diseases has found that Sanofi’s Beyfortus (nirsevimab) provides significant protection against RSV hospitalizations not only during the first season but also into the second RSV season for immunized infants. The NIRSE-GAL study reported an 85.9% reduction in RSV-related lower respiratory tract infection hospitalizations during the first season and a 55.3% reduction during the second season among previously immunized infants.
The universal immunization program achieved a 94.4% coverage rate, with 11,796 of 12,492 eligible infants receiving the treatment. Additional findings included a 78.2% reduction in RSV-related rehospitalizations during the second season and a 30.8% reduction in primary care consultations for acute bronchitis and bronchiolitis.
Beyfortus is a long-acting monoclonal antibody with a 71-day half-life, approved for infants through 24 months of age. Over 11 million infants across more than 45 countries have been immunized since launch. The results were presented at the RSVVW ‘26 conference in Rome.