a1 Department of Veterinary Microbiology and Preventive Medicine, Ames, College of Veterinary Medicine, Iowa State University, Iowa, USA
a2 Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
a3 Department of Animal Science, College of Agriculture, Iowa State University, Ames, Iowa, USA
a4 Harrisvaccines Inc., Ames, Iowa, USA
Influenza virus infects a wide variety of species including humans, pigs, horses, sea mammals and birds. Weight loss caused by influenza infection and/or co-infection with other infectious agents results in significant financial loss in swine herds. The emergence of pandemic H1N1 (A/CA/04/2009/H1N1) and H3N2 variant (H3N2v) viruses, which cause disease in both humans and livestock constitutes a concerning public health threat. Influenza virus contains eight single-stranded, negative-sense RNA genome segments. This genetic structure allows the virus to evolve rapidly by antigenic drift and shift. Antigen-specific antibodies induced by current vaccines provide limited cross protection to heterologous challenge. In pigs, this presents a major obstacle for vaccine development. Different strategies are under development to produce vaccines that provide better cross-protection for swine. Moreover, overriding interfering maternal antibodies is another goal for influenza vaccines in order to permit effective immunization of piglets at an early age. Herein, we present a review of influenza virus infection in swine, including a discussion of current vaccine approaches and techniques used for novel vaccine development.
(Received August 01 2012)
(Accepted November 05 2012)