Development of a DIVA Test Strategy for Canine Influenza

Diva Test PlateDogs in shelters, boarding/training kennels, and day care centers are at highest risk for infection with canine influenza virus (CIV).  Although a vaccine would greatly benefit the health and welfare of dogs at risk by providing protection from infection, vaccination will interfere with the current test for diagnosis of infected dogs. The objective of this study is to develop a diagnostic test strategy that can differentiate infected from vaccinated dogs.

Due to the increasing frequency of canine influenza outbreaks that impact the health and welfare of dogs, a vaccine is urgently needed to provide protection from infection.  Influenza vaccines induce formation of antibodies against proteins important in virus infectivity, but these antibodies will interfere with current serological assays for CIV infection, thereby creating a diagnostic dilemma. The objective of this study to develop and validate a diagnostic test strategy that differentiates infected and vaccinated dogs. The basis of the strategy is that infected dogs have antibodies to the viral H3 and NS1 proteins, while vaccinated dogs have antibodies to H3, but not NS1. Molecular techniques will be used to clone, express, purify, and then utilize the CIV H3 and NS1 proteins in an ELISA to capture infection-specific antibodies. Diagnostic accuracy of the ELISA will be determined by testing archived serum samples from unvaccinated/uninfected dogs, unvaccinated/infected dogs, and vaccinated dogs. Development of this differential testing strategy will not only solve the diagnostic dilemma created by vaccination, but will also be useful for future studies on the epidemiology of canine influenza in the face of vaccination.

This study is being conducted by Dr. Tara Anderson and Dr. Cynda Crawford and is funded by Morris Animal Foundation.