FDA Approves RSV Drug

The Federal Drug Administration yesterday approved the first drug to prevent the respiratory syncytial virus, also known as RSV, in children up to 2 years old. RSV, which causes cold-like symptoms but can lead to acute respiratory infections, is the leading cause of hospitalizations for infants in the US (see overview).

The new drug from AstraZeneca and Sanofi, called nirsevimab and marketed under the brand name Beyfortus, is a monoclonal antibody (clones of real antibodies) meant to be administered through a single shot to infants entering their first RSV season, which lasts from fall to spring and peaks in winter. It may also be administered to children under 2 who are entering their second RSV season. See the difference between an antibody shot and a vaccine here.

The FDA approved the drug after three clinical trials showed it reduced the risk of RSV infection between 70% to 75% among infants and children under 2 years old. The drug has previously been approved in Canada, Europe, and the UK.