DNA Vaccination Elicits Protective Immune Responses against Pandemic and Classic Swine Influenza Viruses in Pigs

September 28, 2011 — 

Swine influenza is a highly contagious viral infection in pigs that significantly impacts the pork industry due to weight loss and secondary infections. There is also the potential of a significant threat to public health, as was seen in 2009 when the H1N1 pandemic strain emerged from reassortment events between avian, swine, and human influenza viruses within pigs. As classic and pandemic H1N1 strains now circulate in swine, an effective vaccine may be the best strategy to protect the pork industry and public health. Current inactivated vaccines available for swine influenza protect only against viral strains closely related to the vaccine strain, and egg-based production of these vaccines is insufficient to respond to large outbreaks. DNA vaccines are a promising alternative since they can potentially induce broad-based protection with more efficient production methods. In this study we evaluated the potential of monovalent and trivalent DNA vaccine constructs to 1) elicit both humoral and IFN-γ responses, and 2) protect pigs against viral shedding and lung disease after challenge with pandemic H1N1 or classic swine H1N1 influenza virus. We also compared the efficiency of a needle-free vaccine delivery method to conventional needle/syringe injection. We report that DNA vaccination elicits robust serum antibody and cellular responses after three immunizations, and confers significant protection against influenza challenge. Needle-free delivery elicited improved antibody responses with the same efficiency as conventional injection, and should be considered for development as a practical alternative for vaccine administration.

Gorres JP, Lager KM, Kong WP, Royals M, Todd JP, Vincent AL, Wei CJ, Loving CL, Zanella EL, Janke B, Kehrli ME Jr, Nabel GJ, Rao SS, DNA Vaccination Elicits Protective Immune Responses against Pandemic and Classic Swine Influenza Viruses in Pigs, Clin Vaccine Immunol. 2011 Sep 14. [Epub ahead of print]

Laboratory Animal Medicine, Vaccine Research Center, National Institutes of Health, Bethesda, MD 20892.

PMID: 21918118 [PubMed - as supplied by publisher]