To date, there is no consensus regarding
palivizumab prophylaxis for
respiratory syncytial virus infection. The purpose of this study is to assess the effectiveness of
palivizumab prophylaxis to prevent respiratory syncytial virus-related
infection consultations and hospitalizations in high-risk children <2 y. We studied children <2 y of age with risk factors who had indication of
palivizumab prophylaxis over eight epidemic seasons (2011-2012 to 2018-2019) in Navarra, Spain. Children positives for respiratory syncytial virus by reverse-transcription polymerase chain reaction were compared to negative testers.
Palivizumab was indicated in 1,214 children <2 y of age with risk factors during 2011-2012 to 2018-2019 seasons. A total of 142 high-risk children tested for respiratory syncytial virus were included in the study. From the 35 respiratory syncytial virus-positive confirmed cases, 20 (57%) had received
palivizumab versus 82 (77%) from the 107 negative controls. The effectiveness of prophylactic
palivizumab was 70% (95% CI, 19%-90%) in preventing confirmed clinical
infection and 82% (95% CI, 29%-96%) in preventing hospitalized cases. Our results show that
palivizumab is notably effective for preventing laboratory-confirmed cases of respiratory syncytial virus and hospitalization in high-risk children <2 y of age. For children who have received
palivizumab, the risk of getting sick remains high; thus, other preventive measures are necessary.