Merck received FDA approval for Enflonsia (cesrovimab), a long-acting monoclonal antibody to prevent lower respiratory tract disease caused by respiratory syncytial virus (RSV) in newborns and infants. This approval introduces competitive dynamics alongside Sanofi/AstraZeneca’s Beyfortus in the pediatric RSV prevention landscape. The timing is notable given the abrupt removal of CDC vaccine advisory committee members, creating uncertain regulatory advisory pathways. RSV remains a primary cause of infant hospitalization, and this MAb’s approval is projected to support public health by providing an additional preventive option.