A team from Tulane National Primate Research Center conducted a study that gives support for the use of vaginal microbicide gels in protecting women against the sexual transmission of HIV type 1. The study, funded by grants from the National Institutes of Health and Bristol-Meyers Squibb, used vaginal microbicide gels to protect rhesus macaque monkeys against vaginal transmission of multiple strains of simian/human HIV.
The gels were successful in protecting the monkeys from infection from three different strains of simian/human HIV viruses. "The protection we observed was dose-dependent, and at the higher concentration, robust, in that all the test animals resisted infection," said the researchers.
The microbicide gels targeted one of the main cellular receptors that HIV uses to infect cells. The advantage of the microbicide gels used, called T-1249, over other compounds was that these gels targeted a receptor that is common to most strains of HIV. An ever-increasing number of different HIV strains make protection against the disease very challenging. Whether T-1249 can be developed as a practical microbicide will depend on if it can be successfully formulated at a reasonable cost.
Research on vaginal microbicides has also been conducted at UCLA and the results of that research appeared in the National Academy of Sciences online July 7th issue. UCLA researchers concluded that the vaginal microbicides currently in clinical trials may be the only direct way that women can protect themselves against infection from HIV and other sexually transmitted diseases.
"The antiretroviral drugs within these microbicides are the same as those used to treat people who are infected with HIV, so there is a great expectation that these microbicides will be very effective, but the concern is that these microbicides are going to lead to drug resistance," said Dr. David Wilson, of Australia's University of New South Wales.
If the microbicides are used by HIV-positive women they could lead to drug resistance. In these cases men would likely benefit more than women from their use, because the HIV infection would be less likely to be transmitted from the woman to man.