Abstract
BACKGROUND: After initially recommending palivizumab (PVZ), a monoclonal antibody against respiratory syncytial virus (RSV) for all infants 29 to 32 weeks at birth if <6 months age at season start, the American Academy of Pediatrics (AAP) and Canadian Paediatric Society (CPS) guidelines were revised. British Columbia was the only jurisdiction in North America to restrict eligibility for this group to those with additional risk factors, long before the change in national recommendations. OBJECTIVES: To determine the risk for first season RSV admission for 29 to 32-week gestational age (GA) infants admitted to Victoria Neonatal Intensive Care Unit (NICU) that either received or were denied PVZ prophylaxis. METHODS: Descriptive cohort study of infants eligible for prophylaxis according to earlier CPS guidelines. Instead, BC guidelines for prophylaxis were applied and data for Vancouver Island infants were collected over 10 consecutive RSV seasons. RESULTS: We followed 423 infants. Three hundred and thirty-six (79%) did not receive prophylaxis, of which 10 (3.0%; 95% confidence interval [CI] 1.4% to 5.4%) had an RSV hospitalization before the end of April during their first RSV season versus 3 admissions from 87 (3.5%; 95% CI 0.7% to 10%) infants who received prophylaxis. CONCLUSIONS: Our risk factor approach to RSV prophylaxis for infants born at 29 to 32 weeks GA resulted in a low (average incidence=3.1%) rate of RSV hospitalization. Our approach would offer considerable cost savings to RSV prophylaxis programs that continue to offer routine prophylaxis beyond 28/29 weeks GA at birth.