On July 17, 2023 the FDA approved the drug nirsevimab under the trade name Beyfortus, a monoclonal antibody, for the prevention of RSV. Though the CDC has determined that it can define nirsevimab as a vaccine for their purposes, nirsevimab is not classified as a vaccine by the FDA, American Medical Association or the World Health Organization. On August 3, 2023, the CDC recommended that all infants under eight months of age born during, or entering their first RSV season (late fall through early spring, receive a single dose of Nirsevimab. Infants and young children ages 8 through 19 months who are considered to be at an elevated risk of severe RSV illness are also recommended to receive a dose during their second RSV season.
Nirsevimab is not routinely recommended for use in infants whose mothers received a dose of RSV vaccine during pregnancy. However, infants whose mothers received RSV vaccine during pregnancy may be given a dose under certain circumstances, at the discretion of their health care provider. These circumstances include infants born with congenital conditions that place them at high risk for severe RSV illness (congenital health disease, receipt of intensive care services, oxygen supplementation), those who underwent cardiopulmonary bypass, those born to mothers with immunocompromising conditions, and those born within two weeks of maternal RSV vaccination. No safety or effectiveness data exists on the use of Nirsevimab in infants whose mothers received RSV vaccination during pregnancy.
