Beyfortus® (nirsevimab-alip) offers RSV protection through 5 months based on clinical data with a single dose for most infants. Recommended dosing is based on body weight, with select high-risk children eligible for a second-season dose.1
Beyfortus is indicated for the prevention of RSV lower respiratory tract disease in1:
- 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.
Administration schedule
The ideal timing for Beyfortus dosing is just before the start of the first RSV season or shortly after birth for infants born shortly before or during the RSV season.1,2
Recommended timing of Beyfortus administration for most of the continental US2*
Date of birth:
April 1 through September 30
Administer beginning
October 1
Date of birth:
October 1 through March 31
Administer within 1 week after birth, ideally in the hospital
First RSV season
Neonates and infants born during or entering their first RSV season1
AAP recommends Beyfortus for infants aged <8 months between October 1 and March 312,3*
RSV is seasonal, with infections peaking at certain times throughout the year. A typical RSV season runs roughly from fall through spring, with some exceptions, such as in Florida and Hawaii, where the RSV season may start earlier. In most of the continental US, RSV typically peaks between December and February.1,2,4-6
For full recommendations, which include important guidance, visit the AAP website.
Because the timing of the onset, peak, and decline of RSV activity might vary geographically, providers can adjust administration schedules based on local epidemiology.
- Tropical climates: RSV seasonality might differ in tropical climates, including Southern Florida, Guam, Hawaii, Puerto Rico, US-affiliated Pacific Islands, and US Virgin Islands
- Alaska: 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 the recommended timing of Beyfortus administration.
Second RSV season
Children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season1
Infants and children aged 8 to 19 months at increased risk for severe RSV disease who are recommended to receive Beyfortus when entering their second RSV season include5:
- 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
- American Indian or Alaska Native children
- Children with cystic fibrosis who have either:
- 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
- weight-for-length <10th percentile
Special circumstances
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 circumstances.1
Provides passive immunization that extends through 5 months, the typical length of the RSV season, regardless of birth month1,7
*Timing of administration for RSV immunization may differ in certain areas.2
Weight-based dosing1
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 IM injection.
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).
Recommended dosage of Beyfortus
RSV season |
Body weight at the time of dosing |
Recommended dosage |
| First RSV season | <5 kg | 50 mg by IM injection |
| First RSV season | ≥5 kg | 100 mg by IM injection |
| Second RSV season | Any weight | 200 mg by IM injection (2 x 100 mg) |
Administration and storage1
Administration
- Beyfortus is for IM 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
Storage
- Store in a refrigerator between 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
- Store in original carton to protect from light until time of use
- Do not freeze
- Do not shake
- Do not expose to heat
Beyfortus can be concomitantly administered with childhood vaccines1*
*There is limited experience with the coadministration of Beyfortus and other 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.
AAP recommendations
Considerations regarding maternal vaccination8,9*
Beyfortus is recommended for infants aged <8 months born during or entering their first RSV season:
Whose mother did not receive the RSV maternal vaccine
Whose mother's receipt of the RSV maternal vaccine is unknown
Who were born <14 days after maternal vaccination
Beyfortus may be considered for infants whose mother received the RSV maternal vaccine, if, based on the clinical judgment of the healthcare provider, the potential incremental benefit of administration is warranted. Current recommendations are for a single lifetime dose of the RSV maternal vaccine during pregnancy and that Beyfortus should be used for infants born to mothers who received the RSV vaccine during a previous pregnancy.
*Beyfortus is not needed for most infants aged <8 months whose mother received the RSV maternal vaccine >14 days before birth.10
Beyfortus is the first RSV prevention therapy approved for all infants in the US through their first season1,10
Infants aged <8 months born during or entering their first RSV season are recommended to receive 1 dose of Beyfortus (50 mg for infants <5 kg and 100 mg for infants ≥5 kg).
- Providers should target administration shortly before the start of the season for infants aged <8 months
- For infants born shortly before or entering their first RSV season, Beyfortus should be administered within 1 week of birth, which can be during the birth hospitalization or in the outpatient setting
Children aged 8 to 19 months who are at an increased risk of severe RSV disease and entering their second RSV season are recommended to receive 1 dose of Beyfortus (200 mg administered as 2 IM injections: 2 X 100 mg).
- Providers should target administration shortly before the start of the season for children aged 8 to 19 months who are at an increased risk of severe RSV disease
Season readiness protocol
Start preparing today for the next season
- Reflect: What were your immunization rates from last season?
- Set goals: Set your Beyfortus coverage goal for the next season at the earliest opportunity
- Plan early: Plan ahead so that no infant is left unprotected
Identify eligible patients and be prepared to implement immunization with Beyfortus
Integrate your EHR system now to help improve immunization rates and identify gaps in protection
Why optimize your EHR?
EHR optimization has the potential to improve immunizations rates, quality of care, and potential outcomes for your patients by helping to:
Simplify care management for clinicians and care teams
Inform clinicians and care teams about gaps in care
Identify patients eligible for Beyfortus at the first visit
Your work to help address RSV disease does not end with the RSV season.
To ensure no infant in your practice is left unprotected, utilize your EHR system to pull your 2025-2026 immunization rates to understand where the immunization gaps are and prepare for increased patient immunization in the 2026-2027 RSV season.
Per AAP guidelines1,2:
- All infants born during RSV season (October 1 through March 31) should receive Beyfortus within 1 week of birth, ideally during the birth hospitalization*
- All infants born before the RSV season (April 1 through September 30) should be recalled starting October 1 for their RSV immunization*
*Timing of administration for RSV immunization may differ in certain areas.3
Automate your EHR system to pull your RSV immunization rates and identify eligible infants11
Outside of the RSV season
- Review past season immunization rates
- Discuss with families of eligible infants to prepare to return shortly before the start of the next RSV season to receive Beyfortus
- Consider scheduling a “Beyfortus only” future visit for infants not due for a well-baby visit at the start of the RSV season
Shortly before the RSV season
- Optimize EHRs for identification and easy recognition of patient eligibility
- Establish and update all infant well-baby visit protocols for the administration of Beyfortus
- Review practice scheduling to ensure newborns are seen within the first week of life
- Develop a community outreach plan to educate parents on Beyfortus
During the RSV season
- Add routine orders to ensure administration at well, sick, or sibling visits at the start of the RSV season
- Establish opportunities to administer catch-up doses throughout the season for eligible infants
- Recall infants who have missed the opportunity for immunization against RSV disease
EHRs, well-visit protocols, and routine orders across visit types can assist in integrating Beyfortus into practice
Frequently asked questions
For the vast majority of infants, only one dose of Beyfortus is needed to provide season-long protection. Children up to 24 months who remain at increased risk for severe RSV disease should receive an additional dose during their second RSV season.1
Yes, Beyfortus can be administered concomitantly with childhood vaccines. There is limited experience with the coadministration of Beyfortus and other vaccines. 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.1
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).1
For more information about the dosing and administration of Beyfortus, please contact our representatives at VaccineShop
AAP, American Academy of Pediatrics; EHR, electronic health record; IM, intramuscular; RSV, respiratory syncytial virus; VFC, Vaccines for Children.
Important Safety Information
References: 1. Beyfortus (nirsevimab-alip). Prescribing Information. Sanofi. 2. Immunizations to protect infants. Centers for Disease Control and Prevention. Updated August 18, 2025. Accessed May 28, 2026. https://www.cdc.gov/rsv/vaccines/protect-infants.html 3. Recommended child and adolescent immunization schedule for ages 18 years or younger. American Academy of Pediatrics. Updated February 5, 2026. Accessed May 28, 2026. https://downloads.aap.org/AAP/PDF/AAP-Immunization-Schedule.pdf 4. Rose EB, Wheatley A, Langley G, et al. Respiratory syncytial virus seasonality—United States, 2014-2017. MMWR Morb Mortal Wkly Rep. 2018;67(2):71-76. 5. 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. 6. The National Respiratory and Enteric Virus Surveillance System (NREVSS). Centers for Disease Control and Prevention. Updated June 18, 2025. Accessed June 1, 2026. https://www.cdc.gov/nrevss/php/dashboard/index.html 7. 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. 8. Fleming-Dutra KE, Jones JM, Roper LE, et al. Use of the Pfizer respiratory syncytial virus vaccine during pregnancy for the prevention of respiratory syncytial virus–associated lower respiratory tract disease in infants: recommendations of the Advisory Committee on Immunization Practices—United States, 2023. MMWR Mortal Wkly Rep. 2023;72(41):1115-1122. 9. Maternal respiratory syncytial virus vaccination. American College of Obstetricians and Gynecologists. Updated October 2025. Accessed June 1, 2026. https://www.acog.org/clinical/clinical-guidance/practice-advisory/articles/2023/09/maternal-respiratory-syncytial-virus-vaccination 10. RSV immunization guidance for infants and young children. Centers for Disease Control and Prevention. Updated August 18, 2025. Accessed June 1, 2025. https://www.cdc.gov/rsv/hcp/vaccine-clinical-guidance/infants-young-children.html 11. Nirsevimab implementation guide. American Academy of Pediatrics. Updated October 12, 2023. Accessed June 1, 2025. https://static1.squarespace.com/static/6058ce5fd8b5963ae8b84e35 t/6536ab42dbac62056a698d36/16980816
