Beyfortus® (nirsevimab-alip) 50 mg and 100 mg injection is a single dose timed to the RSV season for the vast majority of infants1
The ideal timing for Beyfortus dosing is just before or near the start of the first RSV season or from birth for infants born shortly before or during the RSV (respiratory syncytial virus) season1
Beyfortus is indicated for the prevention of respiratory syncytial virus (RSV) lower respiratory tract disease in:
- Neonates and infants born during or entering their first RSV season.
- Children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season.
Office: May be given at regularly scheduled 2-, 4-, or 6-month well-baby visits
Hospital: If not given at the hospital prior to discharge, administer Beyfortus at the first office visit, within 1 week of birth2
- For children undergoing cardiac surgery with cardiopulmonary bypass, an additional dose of Beyfortus is recommended as soon as the child is stable after surgery; please consult the Prescribing Information for complete information on dosing in these circumstances1
- Second season: children up to 24 months of age, regardless of body weight, who remain vulnerable1:
- 1 x 200 mg dose administered as 2 IM injections (2 x 100 mg)
Provides passive immunization that extends through 5 months, the typical length of the RSV season, regardless of birth month1,3
Due to variability in RSV seasonality, there are regional considerations for Beyfortus administration3
ACIP Regional Administration Guidelines3
- Because the timing of the onset, peak, and decline of RSV activity might vary geographically, providers can adjust administration schedules based on local epidemiology
- RSV seasonality in tropical climates (including southern Florida, Guam, Hawaii, Puerto Rico, US-affiliated Pacific Islands, and US Virgin Islands) might differ
- In Alaska, RSV seasonality is less predictable, and the duration of RSV activity is often longer than the national average duration
- Providers in these jurisdictions should consult state, local, or territorial guidance on timing of Beyfortus administration
Second RSV Season Guidelines3
Infants and children aged 8-19 months with increased risk for severe disease who are recommended to receive Beyfortus when entering their second RSV season include:
- Children with chronic lung disease of prematurity who required medical support (chronic corticosteroid therapy, diuretic therapy, or supplemental oxygen) any time during the 6-month period before the start of the second RSV season
- Severely immunocompromised children
- Children with cystic fibrosis who have either:
1) manifestations of severe lung disease (previous hospitalization for pulmonary exacerbation in the first year of life or abnormalities on chest imaging that persist when stable), or
2) weight-for-length <10th percentile - American Indian or Alaska Native children
Single-dose, pre-filled syringe for convenient administration1
A single dose for the vast majority of infants based on weight1
Product images are representative of scale - actual size of packaging may be different.
First RSV season: neonates and infants
The recommended dosage of Beyfortus for neonates and infants born during or entering their first RSV season is based on body weight and is administered as a single intramuscular (IM) injection.
Recommended dosage of Beyfortus for their first RSV season
| Body Weight at the Time of Dosing | Recommended Dosage |
| <5 kg | 50 mg by IM injection |
| ≥5 kg | 100 mg by IM injection |
Second RSV season: children who remain at increased risk for severe RSV disease
For children up to 24 months of age, regardless of body weight, who remain at increased risk for severe RSV, the recommended dosage of Beyfortus is a single 200 mg dose administered as 2 IM injections (2 x 100 mg).
Children undergoing cardiac surgery with cardiopulmonary bypass
For children undergoing cardiac surgery with cardiopulmonary bypass, an additional dose is recommended as soon as the child is stable after surgery. Please consult the Prescribing Information for complete information on dosing in this circumstance.
Can be administered concomitantly with any childhood vaccines
There is limited experience of Beyfortus coadministration with vaccines. In clinical trials, when Beyfortus was given with routine childhood vaccines, the safety and reactogenicity profile of the coadministered regimen was similar to the childhood vaccines given alone. Beyfortus should not be mixed with any vaccine in the same syringe or vial. When administered concomitantly with injectable vaccines, they should be given with separate syringes and at different injection sites.
Practical considerations for Beyfortus
How should Beyfortus be administered?1
- Beyfortus is for intramuscular injection only, preferably in the anterolateral aspect of the thigh
- The entire contents of the syringe should be administered intramuscularly
- The gluteal muscle should not be used routinely as an injection site because of the risk of damage to the sciatic nerve
How should Beyfortus be stored?1
- Store in a refrigerator 36° F to 46° F (2° C to 8° C)
- Beyfortus may be kept at room temperature 68°F to 77°F (20°C to 25°C) for a maximum of 8 hours. After removal from the refrigerator, Beyfortus must be used within 8 hours or discarded
- Do not freeze
- Do not shake or expose to direct heat
- Store in original carton to protect from light until time of use
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Demonstrated Safety and Efficacy Profile1
Important Safety Information
References: 1. Beyfortus (nirsevimab-alip). Prescribing Information. Sanofi. 2. Jones JM, Fleming-Dutra KE, Prill MM, et al. Use of nirsevimab for the prevention of respiratory syncytial virus disease among infants and young children: recommendations of the Advisory Committee on Immunization Practices—United States, 2023. MMWR Morb Mortal Wkly Rep. 2023;72(34):920-925. 3.Obando-Pacheco P, Justicia-Grande AJ, Rivero-Calle I, et al. Respiratory syncytial virus seasonality: a global overview. J Infect Dis. 2018;217(9):1356-1364.
