Immunogenicity of RepliVAX WN, a novel single-cycle West Nile virus vaccine

We recently reported that immunization with RepliVAX WN, a single-cycle West Nile virus (WNV) vaccine, protected mice against WNV challenge. We have extended these studies by characterizing the RepliVAX WN-elicited antibody and T cell responses. WNV-specific IgG antibody responses comprised predominantly of IgG2c and IgG2b subclasses were detected 8 months after immunization. Vigorous WNV-specific CD4+ and CD8+ T cell responses directed at both structural and nonstructural WNV proteins were detected which were characterized by cytolytic activity and secretion of IFN-γ and TNF-α. Importantly, RepliVAX WN immunization resulted in vigorous CD8+ memory T cell responses detected at 8 months after immunization.