A University of Florida researcher has discovered an unexpected link between the viruses that cause feline and human AIDS: Cats vaccinated with an experimental strain of the human AIDS virus appear to be at least as well-protected against the feline version of the disease as those immunized with the vaccine currently used by veterinarians.
The surprise finding may mean cats with feline immunodeficiency virus, also known as FIV or feline AIDS, could eventually be treated even more effectively using some form of the experimental human vaccine.
Researcher Janet Yamamoto, a professor at UF's College of Veterinary Medicine, also theorizes that these emerging relationships between the two viruses could one day lead to a vaccine for human AIDS.
Results from Yamamoto's research can be previewed in today's (Sept. 8) online issue of the journal AIDS.
FIV is a natural infection of domestic cats that results in an immunodeficiency syndrome resembling HIV infection in humans. Since its discovery in 1987, FIV infection of cats has been used in vaccine studies as a small-animal model of human AIDS.
"We were the first to demonstrate that you can make an effective vaccine against a virus in the AIDS family of viruses," said Yamamoto, a co-discoverer of FIV.
Yamamoto holds the patent on the only approved vaccine available through veterinarians to protect cats against FIV. Her most recent studies have attempted to improve the efficacy of that vaccine by using strains of FIV found in cats in which the disease had not progressed for some reason over several years.
To determine the extent to which the human and feline AIDS viruses react to each other, and any implications that might exist for vaccine efficacy, Yamamoto began experimenting with long-term, nonprogressive strains of FIV that led to the current commercial vaccine. Now she is working on an HIV vaccine consisting of HIV virus from long-term, nonprogressing individuals.
"We purposely made vaccines with strains that weren't virile," Yamamoto said. "We found that whenever we tried using less virulent strains of virus, we were able to make a better vaccine."
Yamamoto's team was also surprised to discover that a core protein found in HIV also effectively protects cats against FIV.