Protective immunity induced by Respiratory Syncytial Virus Glycoprotein fragment in Neonatal Mice

Abstract

Respiratory syncytial virus (RSV) is the major cause of severe lower respiratory tract infection in infants and the elderly worldwide. The significant morbidity and mortality associated with this infection underscores the urgent need for an RSV vaccine development. In this study, we firstly showed that intranasal administration of RSV glycoprotein core fragment (Gcf) to neonatal mice was capable of inducing systemic humoral immune responses and had protective efficacy against RSV without lung eosinophilia, though antibody response was shifted to Th2. Next, we examined whether the presence of maternal anti-RSV antibodies affects the responsiveness and protection efficacy of Gcf in newborn mice, since infants can have RSV specific maternal antibodies due to frequent re-infection of RSV to adults. Intranasal administration of Gcf induced antibody response, IFN-γ secretion and protected mice against RSV challenge without lung eosinophilia even in the presence of high level of RSV-specific maternal antibodies. Thus, our study suggests that Gcf can be applied as an effective and safe RSV vaccine during the neonatal period.