Recombinant PIV5 vaccine encoding the influenza hemagglutinin protects against H5N1 highly pathogenic avian influenza virus infection following intranasal or intramuscular vaccination of BALB/c mice.

Department of Infectious Diseases, University of Georgia, College of Veterinary Medicine, Athens, GA 30622.
Journal of Virology (Impact Factor: 4.65). 10/2012; DOI: 10.1128/JVI.02330-12
Source: PubMed

ABSTRACT New approaches for vaccination to prevent influenza virus infection are needed. Emerging viruses, such as H5N1 highly pathogenic avian influenza (HPAI) virus, pose not only pandemic threats, but also challenges in vaccine development and production. Parainfluenza virus 5 (PIV5) is an appealing vector for vaccine development and we have previously shown that intranasal immunization with PIV5 expressing the hemagglutinin from influenza virus was protective against influenza virus challenge. While intranasal immunization is an appealing approach, PIV5 may have potential to be utilized in other formats, prompting us to test the efficacy of rPIV5-H5, which encodes the HA from H5N1 HPAI virus, in different vaccination schemes. In the BALB/c mouse model, a single intramuscular or intranasal immunization with a live rPIV5-H5 (ZL46) rapidly induced robust neutralizing serum antibody responses and protected against HPAI challenge, although mucosal IgA responses primed by intranasal immunization more effectively controlled virus replication in the lung. The rPIV5-H5 vaccine incorporated the H5 HA into the virion, and so we tested the efficacy of an inactivated format of the vaccine. Inactivated rPIV5-H5 primed neutralizing serum antibody responses and controlled H5N1 virus replication, although similar to other H5 antigen vaccines, it required a booster immunization to prime protective immune responses. Taken together, these results suggest that rPIV5-HA vaccines and H5-specific vaccines in particular, may be utilized in multiple formats and by multiple routes of administration. This could avoid potential contraindications based upon intranasal administration alone and provide opportunities for broader applications, with the use of a single vaccine vector.

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