Neonatal immunization with respiratory syncytial virus glycoprotein fragment induces protective immunity in the presence of maternal antibodies in mice (P4277)

Abstract

Abstract Respiratory syncytial virus (RSV) is the major cause of severe lower respiratory tract infections in infants and the elderly worldwide. The significant morbidity and mortality associated with this infection underscores the urgent need for development of an RSV vaccine. In this study, we first show that intranasal administration of RSV glycoprotein core fragment (Gcf) to neonatal mice can induce systemic humoral immune responses and protective immunity against RSV without causing lung eosinophilia, although antibody response was shifted to a Th2 response. 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 since adults are frequently reinfected with RSV. Intranasal administration of Gcf induced antibody response and IFNγ secretion and protected mice against RSV challenge without lung eosinophilia even in the presence of high levels of RSV-specific maternal antibodies. Thus, our findings suggest that Gcf may be an effective and safe RSV vaccine during the neonatal period.