VANCOUVER, British Columbia (AP) — The U.S. government pledged $100 million Tuesday to help develop virus-killing creams that would let women protect themselves from AIDS without relying on their partners.
The goal is to create alternatives to condoms that women can use without men’s permission — especially creams that protect against HIV but would still allow them to get pregnant.
Donna E. Shalala, U.S. secretary of health and human services, said the National Institutes of Health and the Centers for Disease Control and Prevention will spend the $100 million over the next four years to speed development of such products.
“Today, too often, women must rely solely on their male partner for protection from HIV. And in too many cases, that means no protection at all,” she said at the 11th International Conference on AIDS.
The CDC’s Dr. Bruce Weniger said such strategies are especially needed in Asia, where men often become infected by prostitutes and then bring the virus home to their wives. These women are often unable or unwilling to insist that their husbands use condoms.
“Women need some product they can use that will protect them without their sex partner’s knowledge or consent,” he said.
Worldwide, 40 percent of the 21 million people infected with HIV are women. Most of them caught the virus through heterosexual intercourse.
Dr. Christopher Elias of the Population Council, based in Bangkok, Thailand, said that even if new HIV-killing products are developed, condoms will remain the cornerstone of AIDS prevention, since they are highly effective.
“Negotiating consistent condom use, however, is not always feasible for many women,” he said.
He also said the new products might provide alternatives to condoms for oral and anal sex for both heterosexual and homosexual couples, although they have not been tested for those purposes.
Because of the time needed to check the safety and effectiveness of vaginal chemicals, Elias said it is unlikely any new products will reach the market before the end of the decade.
Several major studies are under way in Africa of nonoxynol-9, the familiar over-the-counter spermicide, to see if it also stops HIV, as many believe.
But because nonoxynol-9 irritates the vaginal lining, some worry that it might actually increase the risk of AIDS, especially if used several times a day by those who have frequent sex, such as prostitutes.
Reformulated versions of other proven sperm killers, such as the antiseptic chlorhexidine, are also being considered, in part because they are less irritating.
Elias said other possible products being developed include:
ù C31G, a mixture of two surfactants — a type of detergent — by disrupting cell membranes, appears to be better than nonoxynol-9 against the bacteria chlamydia. Early safety testing is under way.
ù Buffering agents that keep acid levels in the vagina high may also inhibit HIV, and human studies are in the planning stages.
ù Suppositories of the bacteria Lactobacillus crispatus, which produces hydrogen peroxide, will also undergo testing soon.
ù At least two examples of another potential group of anti-AIDS substances called sulphated polymers have entered initial testing to see if they irritate the vagina.
ù An HIV-killing compound called PMPA protects monkeys from vaginal exposure to SIV, the simian version of HIV, as does another called N-docosanol. Whether either of these will reach human testing is not yet clear.
Elias said these developments are hampered by lack of knowledge about exactly which cells in the female reproductive tract become infected by HIV. Another drawback is that no animals are easily infected with HIV, so testing is difficult.
“We must leap from relatively simple vaginal irritation studies to large-scale, extremely costly clinical efficacy evaluations,” Elias said.
He noted that many pharmaceutical companies have avoided the field because of concerns about liability, the difficulty of getting products approved and doubts about their profitability.