What is the recommended Respiratory Syncytial Virus (RSV) prophylaxis schedule for high-risk infants using palivizumab (Synagis)?

RSV Prophylaxis Schedule for High-Risk Infants Using Palivizumab (Synagis)

Palivizumab prophylaxis should be administered as 5 monthly doses of 15 mg/kg by intramuscular injection, typically beginning in November and continuing through March for most areas of the United States. 1, 2

Eligibility Criteria for Prophylaxis

First Year of Life

• Infants born before 29 weeks, 0 days' gestation 1
• Infants with chronic lung disease (CLD) who received medical therapy (supplemental oxygen, bronchodilator, diuretic or chronic corticosteroid therapy) within 6 months before the start of the RSV season 1
• Infants with hemodynamically significant congenital heart disease (CHD) who are 24 months of age or younger 2
• Children with pulmonary abnormality or neuromuscular disease that impairs the ability to clear secretions from the upper airways 1
• Infants with congenital abnormalities of the airway or neuromuscular conditions that compromise handling of respiratory tract secretions 1

Second Year of Life

• Preterm infants born at <32 weeks, 0 days' gestation who required at least 28 days of oxygen after birth and who continue to require supplemental oxygen 1
• Children with CLD who continue to require medical therapy 1
• Children with severe immunodeficiency 1
• Children who undergo cardiac transplantation during the RSV season 1

Dosing Schedule

• Dose: 15 mg/kg body weight by intramuscular injection 2
• Frequency: Monthly throughout the RSV season 1, 2
• Maximum doses: 5 monthly doses (no more than 5 doses are recommended within the continental United States) 1
• Timing:
  • If starting in November: Continue for 5 monthly doses (through March) 1
  • If starting in October: Final (5th) dose should be administered in February 1

Special Considerations

• Post-surgical dosing: Children who undergo cardiac bypass or extracorporeal membrane oxygenation should receive an additional dose of palivizumab (15 mg/kg) after the procedure, even if sooner than a month from the previous dose 1
• Hospital discharge: Infants in a neonatal unit who qualify for prophylaxis may receive the first dose 48 to 72 hours before discharge to home or promptly after discharge 1
• Breakthrough RSV infection: If a child receiving monthly palivizumab prophylaxis experiences a breakthrough RSV hospitalization, monthly prophylaxis should be discontinued due to the extremely low likelihood (<0.5%) of a second RSV hospitalization in the same season 1

Efficacy and Limitations

• Palivizumab reduces RSV hospitalization rates by 55% overall 3, 4
• Prophylaxis is not effective for treatment of established RSV disease 1
• Prophylaxis is not recommended for primary asthma prevention or to reduce subsequent episodes of wheezing 1
• A full 5-dose regimen is important, as simulations show that 3-dose regimens result in inadequate protection during months 4 and 5 of the RSV season 5

Additional Preventive Measures

• Keep high-risk infants away from crowds and situations where exposure to infected people cannot be controlled 1
• Restrict participation in group child care during RSV season when feasible 1
• Practice careful hand hygiene 1
• Ensure all eligible infants and their contacts receive influenza vaccine and other age-appropriate immunizations 1
• Eliminate exposure to tobacco smoke 1

Common Pitfalls

• Underdosing with fewer than 5 monthly doses for a typical 5-month RSV season can result in inadequate protection 5
• Delaying initiation of prophylaxis until after the RSV season has started may leave infants unprotected during early exposure 2
• Failure to administer an additional dose after cardiac bypass surgery can result in suboptimal protection due to a 58% decrease in palivizumab serum concentration following this procedure 1
• Despite eligibility criteria, studies suggest that only about 34% of eligible children actually receive palivizumab, indicating potential gaps in implementation 6