All infants younger than 8 months of age who are born during--or who are entering--their first RSV season (typically fall and winter) should have this immunization.
Respiratory Syncytial Virus (RSV) is one of the many viruses that cause respiratory illness. It spreads like a cold virus from person to person and is the most common cause of hospitalization in children under age 1 year. To prevent severe RSV disease in infants, an immunization called nirsevimab (brand name Beyfortus) can be given as an injection and may be included with or between your baby's routine immunizations.
The shot works a little differently than a vaccine. It provides antibodies that start working to protect babies right away. The protection lasts throughout a typical RSV season.
Some babies will be protected by a maternal RSV vaccine, given to the mother during pregnancy. Except in rare circumstances, most infants younger than 8 months of age do not need nirsevimab if they were born 14 or more days after their mother got an RSV vaccine.