Merck Wins US Approval for Shot to Prevent Infant RSV (1)

Merck & Co. won US approval for a shot that protects against RSV, the most common cause of hospitalization among infants.

The Food and Drug Administration approved Merck’s preventative drug for RSV, or respiratory syncytial virus, for children under 1, the agency said Monday. In clinical trials, Merck’s shot reduced the rate of RSV infection by 60% compared with placebo over five months and slashed the number of hospitalizations by 84%.

Merck’s drug, an injectable antibody vaccine called Enflonsia, will compete against a similar product called Beyfortus from partners Sanofi SA and AstraZeneca Plc. Beyfortus, which won US ...