Dr. John T. "Jack" Bryans, an equine researcher who developed numerous vaccines, died Saturday night from cancer at his home in Lexington. He was 80.Bryans was internationally recognized for his research into infectious diseases. He also was a friend to many in the horse community. Among them was Henry White, who ran Plum Lane Farm for years. "He was a great friend but was more like a brother to me than a friend," White said Sunday evening. "Because of the vaccines he developed, he has touched every person that breeds a horse."For 13 years, Bryans worked with Dr. E. Roger Doll, and the pair discovered the virus causing equine viral arteritis and equine viral abortion and developed vaccines for both. Bryans also developed the vaccines for salmonellosis and strangles, and a blood test to detect contagious equine metritis.Bryans was a native of Patterson, N.J., and received a B.S. degree from Florida Southern College, a M.S. degree in microbiology from the University of Kentucky, and a Ph.D. in microbiology from Cornell University. He first worked for UK beginning in 1954 as a virologist, and became a professor of veterinary science in 1960. He was named chairman of the Department of Veterinary Science in 1973, and was given the title of Distinguished Alumni Professor in 1987.He was one of 12 scientists honored in December of 1990 as the first inductees into the Equine Research Hall of Fame established by the University of Kentucky Equine Research Foundation.During his career, Bryans authored more than 100 articles, contributed to eight books, and obtained five patents. He was the organizer of the first four International Conferences on Equine Infectious Diseases, and received an honorary doctor of veterinary medicine degree from the University of Berne, Switzerland, and was elected to the Academy of Veterinary Science at the University of Barcelona.Bryans is survived by his wife, Louise, and two daughters. His brother-in-law is retired veterinarian Ed Fallon.