Beyfortus (Nirsevimab)
Monoclonal antibody to prevent RSV in newborns · Sanofi Pasteur
Prevents
Dosing schedules
Infants in their first RSV season: 1 dose by weight
For: Infants (0–1 year)
| Dose | Age | Minimum interval from previous dose |
|---|---|---|
| Single dose (Beyfortus) | Before or during the RSV season; under 5 kg: 50 mg, 5 kg or more: 100 mg | – |
Children up to 24 months who remain at risk of severe RSV in their second RSV season: one 200 mg dose. Children undergoing heart surgery with cardiopulmonary bypass have a separate dose.
Source: Recommended vaccination schedules for all ages in Vietnam (2026 edition). Reviewed on 07/10/2026.
Special precautions
Protects infants through their first RSV season with a single intramuscular dose.
Pregnancy and breastfeeding
For newborns and young children only