First versus second year respiratory syncytial virus prophylaxis in chronic lung disease (2005–2015)

Children aged <2 years with chronic lung disease (CLD) have a 10-fold higher risk for respiratory syncytial virus-positive hospitalization (RSVH) compared to healthy term infants. Based on the updated position statements, we compared respiratory-related illness hospitalization (RIH) and RSVH risks in CLD children who received palivizumab during the first year (FY) versus second year (SY) of life in the Canadian Registry of Palivizumab (CARESS). Demographic data were collected at enrolment and RIH events recorded monthly from 2005 to 2015. Eight hundred forty-seven FY and 450 SY children with CLD were identified. SY children had a lower gestational age (27 versus 29 weeks) and required more days of respiratory support (64 versus 43), oxygen therapy (108 versus 55), and length of stay (118 versus 73) during the neonatal course compared to FY children; all p < 0.0005. RIH rates were 12.2 (FY) and 18.2 (SY), and RSVH rates were 2.3 (FY) and 3.9 (SY). Cox regression showed similar hazards for both RIH (hazard ratio 0.9, 95% CI 0.6–1.6, p = 0.812) and RSVH (hazard ratio 1.1, 95% CI 0.4–2.9, p = 0.920).Conclusions: SY and FY children had similar risks for RIH and RSVH. The findings imply that SY children with CLD are correctly selected for palivizumab based on neonatal illness severity and merit prophylaxis.What is Known:• Children with chronic lung disease have a 10-fold higher risk for RSV-positive hospitalization in comparison to healthy term infants and commonly receive palivizumab prophylaxis as a preventative measure against serious RSV-related lower respiratory tract infections.• The American Academy of Pediatrics [2] and the Canadian Paediatric Society [30] have recently modified their recommendations for RSV prophylaxis in children with chronic lung disease, limiting palivizumab to either those <32 weeks gestation or those in the first year of life who are oxygen dependent or require medical therapy for the treatment of their condition.What is New:• Children with chronic lung disease receiving an additional course of palivizumab in their second year of life were determined to be at similar risk for both respiratory illness-related hospitalization and RSV-positive hospitalization as palivizumab-naïve children enrolled in the first year of life in the Canadian Registry for palivizumab (CARESS).• CARESS physicians are correctly identifying high-risk children with chronic lung disease in their second year of life, whom they believe will benefit from an additional year of palivizumab prophylaxis, based on neonatal illness severity.