The Potential of Neuraminidase as an Antigen for Nasal Vaccines To Increase Cross-Protection against Influenza Viruses
Atsushi Kawai, Yasuyuki Yamamoto, Takuto Nogimori, Kohei Takeshita, Takuya Yamamoto, Yasuo Yoshioka
Abstract
Because mismatch between vaccine strains and epidemic strains cannot always be avoided, the development of influenza vaccines that induce broad cross-protection against antigenically mismatched heterologous strains is needed. Although the importance of NA-specific antibodies to cross-protection in humans and experimental animals is becoming clear, the potential of NA as an antigen for providing cross-protection through nasal vaccines is unknown. We show here that intranasal immunization with NA confers broad cross-protection in the upper respiratory tract, where virus transmission is initiated, by inducing NA-specific IgA that recognizes a wide range of epitopes. These data shed new light on NA-based nasal vaccines as powerful anti-influenza tools that confer broad cross-protection.