Nirsevimab Administration

Routine Dosing

The single dose should be administered to all infants <8 months of age born during or entering their first RSV season (typically starting October 1 through March 31 in most of the continental US). Eligibility is determined by age at the time of administration. Those with a prolonged hospital stay should get it shortly before or promptly after discharge. In tropical climates and Alaska where the RSV season may be different than the rest of the US, clinicians should consult state, local or territorial guidance on timing. 

Dosing by Weight/Age

A single dose should be administered to  

• Infants weighing <5 kg: 50 mg dose (purple plunger rod)
• Infants weighing ≥5 kg: 100 mg dose (light blue plunger rod)
• Children receiving nirsevimab in their second RSV season should receive a single dose of 200 mg, administered through 2 separate 100 mg IM injections. 

Dosing for Children at High Risk During Second RSV Season

Children ages 8-19 months who remain vulnerable to severe RSV disease when entering their second RSV season should receive a dose of nirsevimab. 

This includes: 

• 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.
• Children who are severely immunocompromised. 
• Children with cystic fibrosis who have 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 have weight-for-length that is <10th percentile.
• American Indian and Alaska Native children (note that this is a new group for whom second-season prophylaxis is recommended in contrast to the current palivizumab recommendations). 

Nirsevimab and Palivizumab

• If nirsevimab is administered, palivizumab should not be administered later that season.
• If palivizumab was administered initially for the season and <5 doses were administered, the infant should receive 1 dose of nirsevimab. No further palivizumab should be administered.
• If palivizumab was administered in season 1 and the child is eligible for RSV prophylaxis in season 2, the child should receive nirsevimab in season 2, if available. If nirsevimab is not available, palivizumab should be administered as previously recommended.  

Reporting Adverse Events

Adverse events when giving nirsevimab alone should be reported to the FDA’s MedWatch Adverse Event Reporting Program.  

If an adverse event occurs while co-administering nirsevimab with a vaccine, it should be reported to the Vaccine Adverse Event Reporting System. 

Additional Information

• AAP Immunization Administration in Your Practice