Palivizumab prophylaxis for respiratory syncytial virus in Canada: utilization and outcomes.

Objective: To provide information on the use and outcomes of palivizumab prophylaxis in children at high risk of serious respiratory syncytial virus (RSV) infection.

Design: Observational, prospective, longitudinal, multicenter study.

Setting: Eighteen hospitals and pediatric clinics located in six provinces across Canada.

Patients: Infants enrolled in the palivizumab Special Access Programme of Canada's Therapeutic Products Programme throughout the 1999 to 2000 RSV season. Most were premature infants born at < or = 32 weeks of gestation and/or had bronchopulmonary dysplasia.

Methods And Main Outcome Measures: Neonatal and demographic data were recorded for each subject. The parent/caregiver was contacted on a monthly basis until the end of the RSV season to obtain information on palivizumab utilization and compliance as well as incidence and severity of respiratory infections.

Results: There were 444 evaluable subjects who each received 1 to 7 injections of palivizumab for a total of 1702 doses from September 1999 to April 2000. Most subjects received 5 injections with high compliance. Prophylaxis was discontinued in 2% of children. There were 116 clinical events or hospitalizations involving respiratory tract infections reported in 91 children. Eighty-six of these were managed in an outpatient setting, and 30 required hospitalization. The estimated incidence of hospitalization for RSV-positive lower respiratory tract infections (LRTIs) was 2.4%. Hospitalization for RSV LRTI occurred more often in children with bronchopulmonary dysplasia (6.0%) than in those with prematurity only (1.6%).

Conclusions: This study demonstrates that prophylaxis with palivizumab during the RSV season was associated with a low rate of hospitalization for RSV-positive LRTIs. Palivizumab was well-tolerated, and compliance was high. The findings confirm the results of the major randomized clinical trial of palivizumab and demonstrate the safety and effectiveness of RSV prophylaxis.