Nirsevimab: A New Option for Protecting Newborns from RSV, the Leading Cause of Infant Hospitalization in the US

The US Food and Drug Administration (FDA) has approved the use of nirsevimab, a new treatment marketed as Beyfortus, to protect newborns from respiratory syncytial virus (RSV). Nirsevimab is not a vaccine but a form of passive immunity that involves using ready-made antibodies to block the virus from infecting healthy cells. The treatment is given as a single injection before the RSV season, which typically occurs during the fall and winter months. The FDA’s approval also allows a second injection for infants up to 24 months of age who remain vulnerable through their second RSV season. RSV is the leading cause of hospitalization in infants under one year old in the United States. It can cause serious illness and even death in infants, as well as affecting elderly adults. Cheryl Meany, who participated in an early study testing nirsevimab, believes the treatment kept her twins healthy during their early years. The Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices will review the vaccine’s recommendations, and Pfizer’s vaccine for pregnant women is also under the FDA’s consideration.