A new research model has been developed and successfully used to test a new type of vaccine against West Nile virus (WNV). Maureen Long, DVM, PhD, Dipl. ACVIM, assistant professor at the University of Florida, proved a chimera WNV vaccine was safe and effective using this new research model developed by Dick Bowen, DVM, PhD, of Colorado State University. Long presented her findings on Dec. 5, 2005, at the American Association of Equine Practitioners Convention.

Long says you only have to look as far as the U.S. human blood donor seroprevalence data for 2005 to see that WNV is still a present threat, so veterinarians and horse owners should continue to look for better ways to safeguard horses against the disease.

Scientists have been limited in testing WNV vaccines in recent years because until now, they were unable to consistently infect an unvaccinated (control) horse with WNV and cause consistent clinical signs.

“As a disease is around for awhile, we start getting into better technologies,” Long said. “I think we need to look at these better technologies, get away from using adjuvants (substances that are added to vaccines to improve immune response so less vaccine is needed, but which can cause site reactions), and find solutions that may be more efficacious for a longer duration. Also, these (new vaccines) will have less over-the-counter capability, and put the vaccines, I hope, back into the hands of the practitioner