Newly Approved Drug to Prevent Respiratory Syncytial Virus in Babies and Toddlers

Much news about respiratory syncytial virus (RSV) disease prevention has been focused on new vaccines authorized for use in older adults (NEJM JW Gen Med Jul 20 2023) as well as pregnant women (NEJM JW Infect Dis May 17 2023 and N Engl J Med 2023; 388:1451 and 1465) — but this virus, with its seasonal occurrence, has long been recognized as a significant pathogen in young infants (particularly those with underlying cardiopulmonary disease and prematurity). Beyfortus is the second monoclonal antibody approved for RSV prevention and joins palivizumab (Synagis), which was approved in 1998 but requires monthly injections during RSV season.

The approval of Beyfortus was based on three clinical trials to measure its efficacy in preventing medicall…