Effects of palivizumab prophylaxis on respiratory syncytial virus (RSV) infections in Montenegro

Background. Respiratory syncytial virus (RSV) is one of the most common pathogens causing severe lower respiratory tract disease in infancy and childhood. In newborns, young infants, and in infants with co -morbidities, the risk of severe infection is increased. Current protection against severe RSV infection is immunoprophylaxis with the monoclonal antibody palivizumab. The study aimed to assess the effects of palivizumab prophylaxis in the Republic of Montenegro in comparison to the pre -prophylaxis period. Methods. The study was conducted in prospective/retrospective single center format in Montenegro in the Clinical Center of Podgorica, for the period 2009-2019. Results. A total of 104 high -risk infants in the palivizumab prophylaxis program (2014-2019 RSV seasons) and 168 high -risk children without palivizumab prophylaxis (2009-2013 RSV seasons) were enrolled. A total of 51 children (49.0%) received prophylaxis for prematurity, 33 (31.7%) for bronchopulmonary dysplasia (BPD), 13 (12.5%) for hemodynamically significant heart disease/defect (HSCHD), and 7 (6.8%) for "miscellaneous" indications. In the control group most children had prematurity (101, 60.1%), followed by BPD (59, 35.1%), HSCHD (3, 1.8%), and "miscellaneous" (5, 3.4%) conditions. Readmission to the pediatric intensive care units (PICU) due to RSV infection was significantly lower in prophylaxis group (0.0 vs 16.1%, p<0.001). No lethal outcomes were observed in high -risk children with palivizumab prophylaxis compared to 2.4% in the control group. Conclusions. The introduction of RSV immunoprophylaxis as well as other new protective treatment strategies for high -risk newborns led to significant improvements in infant and childcare in Montenegro. This is the first report on palivizumab prophylaxis in Montenegro, demonstrating the effectiveness and safety of palivizumab use in clinical settings.