The Impact of Palivizumab for Respiratory Syncytial Virus Prophylaxis on Preschool Childhood Asthma.

Background: The respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections in infants and is associated with an increased risk of asthma development. Palivizumab, an RSV prophylactic, reduces RSV-related hospitalizations in high-risk infants, but its impact on long-term asthma outcomes remains unclear. This study compares asthma-related healthcare utilization in preschool children born prematurely between those who received Palivizumab (the Prophylaxis (+) group) and those who did not (the Prophylaxis (-) group).

Methods: This nationwide, population-based retrospective cohort study utilized data from Clalit Healthcare Services in Israel. The study included children born between 32 + 6 and 34 + 6 weeks of gestational age from 2011 to 2018. Descriptive analysis, univariate analysis, and multivariate logistic regression were performed to compare the Prophylaxis (+) and the Prophylaxis (-) groups.

Results: In total, 4503 children were included, with 3287 in the Prophylaxis (+) group and 1216 in the Prophylaxis (-) group. Palivizumab administration was associated with reduced hospitalizations for RSV bronchiolitis (1.8% vs. 3.3%, = 0.003). However, no significant differences were observed in multivariate analysis for long-term asthma outcomes, including asthma diagnosis (OR = 1.04, CI = 0.84-1.30, = 0.7) or emergency department visits for asthma (OR = 0.79, CI = 0.54-1.17, = 0.2). Similarly, Palivizumab administration was not associated with the purchase of short-acting beta-agonists (OR = 1.14, 95% CI 0.98-1.32, = 0.084), inhaled corticosteroids (OR = 1.1, CI = 0.93-1.32, = 0.3), or oral corticosteroids (OR = 1.09, CI = 0.94-1.26, = 0.3).

Conclusions: While Palivizumab effectively reduces RSV acute bronchiolitis in preterm infants, it does not significantly impact long-term preschool asthma-related healthcare utilization.