What are the recommendations for Respiratory Syncytial Virus (RSV) immunization?

RSV Immunization Recommendations

Nirsevimab is recommended for all infants aged <8 months who are born during or entering their first RSV season and for infants and children aged 8–19 months who are at increased risk for severe RSV disease and are entering their second RSV season. 1

Recommendations for Infants and Young Children

First RSV Season (Infants <8 Months)

• All infants aged <8 months who are born during or entering their first RSV season should receive a single dose of nirsevimab (Beyfortus) 1
• Nirsevimab is administered as a single intramuscular injection shortly before or during the RSV season (typically fall through spring) 1, 2
• In most of the continental United States, nirsevimab could be administered from October through the end of March, based on pre-COVID-19 pandemic patterns 1
• Infants with prolonged birth hospitalizations related to prematurity or other causes should receive nirsevimab shortly before or promptly after hospital discharge 1

Second RSV Season (Children 8-19 Months with High Risk)

• Children aged 8–19 months who are at increased risk for severe RSV disease and entering their second RSV season should receive nirsevimab 1
• High-risk groups for second-season dosing include: 1, 2
  • Children with chronic lung disease of prematurity who required medical support (chronic corticosteroid therapy, diuretic therapy, or supplemental oxygen) within 6 months before the start of the second RSV season
  • Children with severe immunocompromise
  • Children with cystic fibrosis who have either severe lung disease or weight-for-length <10th percentile
  • American Indian or Alaska Native children

Timing and Administration

• Only a single dose of nirsevimab is recommended for an RSV season 1
• Nirsevimab may be administered to age-eligible infants and children who have not yet received a dose at any time during the RSV season 1
• Providers in regions with different RSV seasonality (tropical climates including southern Florida, Guam, Hawaii, Puerto Rico, U.S.-affiliated Pacific Islands, and U.S. Virgin Islands, as well as Alaska) should consult state, local, or territorial guidance on timing of administration 1
• Coadministration of nirsevimab with routine childhood vaccines is recommended, in accordance with general best practices for immunization 1
• For preterm infants, the chronologic (not corrected) age should be used to determine timing and eligibility 1

Comparison with Previous Prophylaxis (Palivizumab)

• Before nirsevimab, palivizumab was the only FDA-approved product for RSV prevention in infants and young children 1, 3
• Unlike palivizumab which requires monthly dosing throughout the RSV season, nirsevimab provides protection with a single dose 1, 2
• Palivizumab was recommended by the American Academy of Pediatrics only for children with certain underlying medical conditions (comprising <5% of all infants) 1, 3
• Replacing palivizumab with nirsevimab for eligible children entering their second RSV season is expected to be cost saving 1

Precautions and Contraindications

• Nirsevimab is contraindicated in persons with a history of severe allergic reaction (e.g., anaphylaxis) after a previous dose or to a product component 1, 2
• When administering nirsevimab to children with increased risk for bleeding, providers should follow ACIP's general best practice guidelines for immunization 1

Recommendations for Adults

• For adults aged ≥75 years and adults aged 60–74 years with increased risk for severe RSV disease, a single dose of RSV vaccine is recommended 1
• High-risk conditions in adults include chronic lung disease, heart disease, diabetes, immunocompromise, and residence in nursing homes 1

Reporting Adverse Events

• Adverse reactions after administration of nirsevimab alone should be reported to FDA MedWatch 1
• Adverse reactions after coadministration of nirsevimab with vaccines should be reported to the Vaccine Adverse Event Reporting System (VAERS) 1, 2

Clinical Impact

• RSV is the leading cause of hospitalization among U.S. infants, with approximately 50,000–80,000 RSV-associated hospitalizations and 100–300 RSV-associated deaths occurring annually among infants and children aged <5 years 1
• Most children are infected with RSV during the first year of life, and nearly all have been infected by age 2 years 1
• Premature infants have three times the rate of RSV-associated hospitalization compared to term infants and higher rates of ICU admission 1
• An estimated 79% of infants and children aged <2 years hospitalized with RSV have no underlying medical conditions 1
• Nirsevimab has shown high efficacy in preventing severe RSV-related lower respiratory tract infections in infants 4, 5