ARS | Publication request: Summary of Control Issues for Swine Influenza

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: December 17, 2009
Publication Date: February 3, 2010
Citation: Vincent, A.L., Lager, K.M., Richt, J.A., Ma, W., Janke, B.H. 2010. Summary of control issues for swine influenza [abstract]. International Symposium on Neglected Influenza Viruses. p. 22.

Technical Abstract: Multiple subtypes of endemic swine influenza virus (SIV) co-circulate in the U.S. and Canada (H3N2, H1N1, and H1N2 with a triple reassortant internal gene (TRIG) constellation derived from swine, avian and human influenza viruses). As a result of reassortment events and antigenic drift, four H1 SIV phylogenetic clusters (alpha, beta, gamma, and delta) are now endemic in the U.S. swine population. Inactivated SIV vaccines are commonly used in the U.S. swine industry. Most fully licensed vaccines are multivalent in nature with H1 and H3 subtypes included. In recent years, use of inactivated autogenous vaccines has become increasingly widespread in an attempt to address the dynamic nature of SIV in the U.S. Most autogenous vaccines are also multivalent with various combinations of H1 and H3 subtypes. The major control issues for swine influenza virus include: 1) limited heterologous immunity to inactivated vaccines combined with the complex epidemiology of SIV and 2) previous lack of centralized system for monitoring SIV and updating virus strains in swine vaccines. Issue one will be discussed in detail. One of the highest priorities for the recently launched USDA SIV surveillance plan is to enhance monitoring of the evolution of SIV for relevant vaccine strain selection and diagnostic reagent development. It is critical to understand the dynamic ecology of influenza A viruses in this susceptible host population and improve the vaccine strain selection system for controlling SIV to reduce the risk of reassortment and/or transmission events in the future.