Palivizumab efficacy in preterm infants with gestational age < or = 30 weeks without bronchopulmonary dysplasia.

The present study was designed to determine the efficacy of administration of palivizumab to preterm infants with gestational age (GA) < or = 30 weeks without bronchopulmonary dysplasia (BPD). All patients born with GA < or = 30 weeks without BPD on Day 28 and hospitalized for RSV bronchiolitis in Burgundy (12 hospitals) from December 1 to April 30 of the next year were included in this prospective observational study during five successive RSV seasons (1999-2000, 2000-2001, 2001-2002, 2002-2003, and 2003-2004). Palivizumab was given to premature infants with a gestational age < or = 30 weeks without BPD in the 2002-2003 and 2003-2004 periods only. In the cohort of premature infants with GA < or = 30 weeks without BPD, the respiratory syncytial virus (RSV) bronchiolitis hospitalization rate was reduced significantly (P < 0.01) in the two seasons with palivizumab prophylaxis (2002-2003: 0% and 2003-2004: 2%) versus the three previous RSV seasons (1999-2000: 14.3%; 2000-2001: 16.7%; 2001-2002: 10.2%). The number needed to treat to prevent one hospitalization for RSV bronchiolitis was 6 (95%CI: 4-11). Such favorable results have not been always found in the few available postmarketing epidemiological studies on hospitalization rate after palivizumab prophylaxis. Differences in health care organization could explain those discrepancies.