Vaccination is considered the most effective measure for controlling influenza virus infection, however current vaccination methods are inadequate. Virus-vectored vaccines offer an appealing alternative. Parainfluenza virus 5 (PIV5), a non-segmented, negative-stranded RNA virus (NNSV) in the family Paramyxoviridae is an appealing vector candidate as it has a stable genome without a DNA phase in its life cycle, is readily grown to high titers in approved vaccine cell lines, and infects many mammals without causing disease. Neuraminidase (NA), a glycoprotein found on the surface of influenza A virus as well as virus-infected cells is more conserved than the hemagglutinin surface glycoprotein, the primary antigen in current influenza vaccines. This increases the likelihood of achieving broad protection if used as a vaccine antigen. We show that vaccination with PIV5 expressing the NA from H5N1 highly pathogenic avian influenza (HPAI; rPIV5-N1 (H5N1)) or pandemic H1N1 (rPIV5-N1 (H1N1)) primes robust NA-specific antibody and T cell responses and confers complete protection against homologous (NA-matched) influenza virus challenge. Moreover, immunization also confers significant cross-protection against challenge with heterologous influenza virus within the same NA type. These results suggest that NA can be an effective vaccine antigen and protect against even a stringent challenge, such as with H5N1 HPAI virus, making it an appealing candidate pandemic influenza vaccine.
- Copyright © 2013 by The American Association of Immunologists, Inc.