What is the administration schedule for the Respiratory Syncytial Virus (RSV) vaccine?

RSV Vaccine Administration Schedule

The RSV vaccine nirsevimab is administered as a single dose before or during RSV season for infants, while older adults receive a single seasonal dose of RSVPreF3 or RSVpreF vaccine. 1

RSV Vaccination for Infants and Children

Nirsevimab (Beyfortus)

• Dosing schedule: Single dose only
• Timing: Administered shortly before or during RSV season 1
  • In most of continental US: October through March
  • Infants born during RSV season: Within 1 week of birth
  • Infants with prolonged hospitalizations: Shortly before or after discharge

Target populations:

1. All infants <8 months born during or entering their first RSV season 1

   • 50 mg for infants <5 kg
   • 100 mg for infants ≥5 kg

2. Children 8-19 months at increased risk entering their second RSV season 1

   • 200 mg (administered as two 100 mg injections)
   • Includes children with chronic lung disease, congenital heart disease, and certain American Indian/Alaska Native children

Important considerations:

• Only a single dose is needed per RSV season 1
• Chronological (not corrected) age should be used for preterm infants 1
• Can be co-administered with routine childhood vaccines 1
• Geographic variations in RSV seasonality exist (e.g., Florida, Alaska, tropical regions) 1

Previous Palivizumab Protocol (Historical Context)

Prior to nirsevimab, high-risk infants received palivizumab with the following schedule:

• Monthly injections (every 28-30 days) throughout RSV season 1
• Maximum of 5 doses for most eligible infants 1
• Maximum of 3 doses for premature infants 32-34 weeks with risk factors 1

Studies showed that a reduced 4-dose schedule timed with local RSV epidemics could provide protection comparable to 5 doses 2, 3.

RSV Vaccination for Adults

Adult RSV vaccines (RSVPreF3 or RSVpreF):

• Dosing schedule: Single dose
• Timing: Preferably administered between September and November 1
• Target populations:
  • People ≥50 years with risk factors (COPD, asthma, heart failure, etc.)
  • All adults ≥60 years 1

Co-administration:

• Can be administered concurrently with seasonal influenza vaccines 1
• When co-administered, vaccines should be given at different injection sites 1

RSV Vaccination During Pregnancy

For pregnant persons:

• Dosing schedule: Single 0.5 mL intramuscular dose
• Timing: During 32-36 weeks' gestation, during RSV season (September-January in most of continental US) 1
• Purpose: To prevent RSV-associated lower respiratory tract disease in infants <6 months 1

Clinical Pearls and Pitfalls

• Either maternal RSVpreF vaccination during pregnancy OR nirsevimab for the infant is recommended - both are not needed for most infants 1
• Optimal timing is crucial - administering too early or continuing prophylaxis when RSV is not circulating is not cost-effective 1
• Local RSV epidemiology should guide administration schedules in regions with atypical seasonality 1
• Compliance with the complete dosing schedule is essential for maximum protection - historically, compliance has been lower among Medicaid patients and minorities 4

The shift from monthly palivizumab to single-dose nirsevimab represents a significant advancement in RSV prevention, improving protection while reducing the burden of multiple injections 5.