What is the recommended prevention and treatment approach for Respiratory Syncytial Virus (RSV) in premature infants, particularly those born at less than 29 weeks of gestation or with underlying health conditions?

RSV Prevention in Premature Infants

Premature infants born before 29 weeks gestation should receive palivizumab prophylaxis at 15 mg/kg intramuscularly monthly throughout the RSV season, up to a maximum of 5 doses, starting before RSV season begins if they are younger than 12 months of age at the start of the season. 1, 2

Eligibility Criteria by Gestational Age

Infants ≤28 Weeks Gestation

• Receive prophylaxis if younger than 12 months at the start of RSV season 1, 2
• Maximum of 5 monthly doses throughout the RSV season 1, 2
• This is the highest priority group with strongest evidence for benefit 1

Infants 29-31 Weeks Gestation

• Receive prophylaxis if younger than 6 months at the start of RSV season 3, 1
• Maximum of 5 monthly doses 3, 1
• Recent evidence suggests these infants have significantly higher RSV hospitalization risk than previously recognized 4, 5

Infants 32-34 Weeks Gestation

• Only receive prophylaxis if younger than 3 months at start of RSV season AND have at least one of these risk factors: 3, 1
  • Attends child care 3
  • Has sibling younger than 5 years 3
• Maximum of 3 doses (only until 90 days of age) 3

Additional High-Risk Groups Requiring Prophylaxis

Chronic Lung Disease/Bronchopulmonary Dysplasia

• Infants younger than 24 months with chronic lung disease who required medical therapy (supplemental oxygen, bronchodilators, diuretics, or corticosteroids) within 6 months before RSV season start 1, 2
• Maximum of 5 doses 1

Congenital Heart Disease

• Infants younger than 24 months with hemodynamically significant congenital heart disease 1, 2
• Includes: acyanotic heart disease receiving medication for congestive heart failure, moderate-to-severe pulmonary hypertension, cyanotic heart disease 3
• Do NOT give to infants with hemodynamically insignificant lesions (secundum ASD, small VSD, mild pulmonic stenosis, mild aortic stenosis, mild coarctation, PDA) 3

Neuromuscular Disease and Airway Abnormalities

• Children with neuromuscular disease or congenital airway abnormalities that impair ability to clear secretions from upper airways 1

Dosing Schedule and Administration

Standard Dosing

• 15 mg/kg intramuscularly monthly throughout RSV season 1, 2
• First dose should be given 48-72 hours before hospital discharge or promptly after discharge if infant qualifies during RSV season 3, 1
• Administer in anterolateral thigh (NOT gluteal muscle due to sciatic nerve risk) 2
• Volumes >1 mL should be divided 2

Special Circumstances

• After cardiac bypass surgery: Give additional dose as soon as medically stable, even if less than 1 month from previous dose 3, 1, 2
  • Cardiopulmonary bypass causes 58% decrease in palivizumab levels 3, 1
• Breakthrough RSV infection: Continue monthly prophylaxis until maximum doses completed (3 doses for 32-34 week group, 5 doses for all others) 3, 1

Critical Limitations

What Palivizumab Does NOT Do

• Palivizumab has NO therapeutic benefit for treating established RSV infection—it is ONLY for prevention 6, 2
• Not recommended for primary asthma prevention or reducing subsequent wheezing episodes 1
• Does not interfere with vaccine responses 3

Essential Non-Pharmacologic Prevention Measures

All high-risk infants require these interventions regardless of palivizumab use:

• Complete elimination of tobacco smoke exposure 3, 6
• Avoid crowds and situations where exposure to infected people cannot be controlled 3, 1, 6
• Restrict group child care participation during RSV season when feasible 3, 1
• Strict hand hygiene by all caregivers and family members 3, 6
• Encourage breastfeeding 6, 7
• Ensure influenza vaccination for infant (starting at 6 months) and all household contacts 1, 6

Common Pitfalls to Avoid

• Failing to give additional dose after cardiac bypass surgery—this is critical as serum levels drop by 58% 3, 1
• Attempting to use palivizumab to treat active RSV infection—it has zero therapeutic benefit once infection is established 6, 2
• Discontinuing prophylaxis after breakthrough RSV infection—continue monthly doses until maximum number reached 3, 1
• Giving prophylaxis to 32-34 week infants without documented risk factors—this is not cost-effective and not recommended 3, 1
• Using gluteal muscle for injection—risk of sciatic nerve damage 2

Treatment of Established RSV Infection

If a premature infant develops RSV infection despite prophylaxis or without prophylaxis, management is entirely supportive:

• Assess and maintain adequate hydration 6, 7
• Provide supplemental oxygen only if SpO2 persistently <90% 6, 7
• Hospitalize if: hypoxemia (SpO2 <90%), severe respiratory distress, inability to maintain oral intake, altered mental status, or underlying high-risk conditions 6, 7
• Do NOT use: corticosteroids, ribavirin (except severely immunocompromised), or antibiotics (unless bacterial co-infection documented) 6
• Hand hygiene remains the single most important infection control measure 6