Real-World Studies of Respiratory Syncytial Virus Hospitalizations among Moderate/Late Preterm Infants Exposed to Passive Immunoprophylaxis with Palivizumab

Objective This article aims to assess the real-world effectiveness of palivizumab immunoprophylaxis against respiratory syncytial virus (RSV)-associated hospitalization (RSVH) rates in otherwise healthy moderate/late preterm infants and discuss the role of palivizumab in preventing acute and long-term outcomes. Study Design We identified studies in the PubMed and Embase databases that reported patient-level data on (1) exposure to palivizumab in preterm infants born between 29 and 35 weeks of gestational age (or subsets within this range) <= 2 years of chronological age, and (2) the outcome of RSVH. Results Six studies assessed RSVH in infants this gestational age who had been exposed or not to palivizumab and reported patient-level data. Exposure was associated with a reduction in RSVH rates that was comparable to the reduction seen in controlled clinical trials (weighed mean 4.0-fold reduction). Conclusion RSV immunoprophylaxis in preterm infants within 29 to 35 weeks of gestational age is associated with a considerably lower burden of RSVH.