Women who are fed up with their partners not wearing condoms during sex may soon have a new tool to protect themselves against HIV infection.
Scientists at the University of Utah have created a gel that women can apply internally that works as a "molecular condom" to block the virus from entering the vagina. Their findings were published online yesterday in the journal Advanced Functional Materials.
The distribution of this gel could greatly reduce the transmission of HIV in both developing and developed countries, while offering women a discreet way to take control of their sexual health.
Patrick Kiser, an assistant professor of bioengineering at the University of Utah, worked with a team of scientists to develop a gel that has a slightly acidic pH level, similar to that of the vagina. When the gel comes in contact with semen - which has a more neutral pH level, much like water - it is "activated," Dr. Kiser said. "The gel changes its structure and it becomes more difficult for the virus to move through [it]" he said.
At Toronto's Hassle Free Clinic, the first site in Canada to offer anonymous testing for HIV, sexual-health counsellor Jane Greer has high hopes for this HIV-blocking gel. "We've been talking about microbicides in our line of work as the holy grail for years," she said.
Research into developing a microbicide (gels, rings and films to kill micro-organisms that are inserted in the vagina or the rectum) took off in the mid-1990s, but scientists have stumbled over funding clinical trials or just coming up with a product that works effectively. Some prototypes increased the risk of HIV transmission, Dr. Kiser said.
At this point, the gel's effectiveness has been studied only under a microscope, but Dr. Kiser's team hopes to complete a clinical trial in the next three to five years. He said the gel could also probably be used to protect against herpes and human papillomavirus (HPV) as well as to prevent pregnancy, though it has yet to be tested for its effectiveness in those areas.
For now, the only way women can protect themselves against HIV transmission is by using a female condom. Tests suggest that it is at least as effective as the male condom - the use of which reduces the risk of HIV transmission by 80 per cent - but because part of it sits outside the vagina, Ms. Greer said, it's not popular with women. "I've heard it described as having sex with a plastic bag in you, so it's not ideal," she said.
Another problem is accessibility. Public-health units invest far more in male condoms than female ones for distribution at sexual-health clinics, Ms. Greer said.
In 2005, the United Nations reported that the cost to produce a male condom was three cents (U.S.), while a female condom was 60 cents. Dr. Kiser said the "molecular condom" should cost no more than five cents to produce each dose, with a shelf price comparable to male condoms.
"If you're talking about impacting the HIV/AIDS pandemic, you're really concerned about engineering technologies that are … extremely inexpensive and simple that can be used in the developing world," he said.
While developing countries - particularly those in sub-Saharan Africa - have the world's highest rates of HIV/AIDS, Ms. Greer said the gel has the potential to dramatically cut the rates of infection in Canada.
In 2006, the Public Health Agency of Canada estimated that 20 per cent of people living with HIV were women. The primary way the virus is transmitted to this population is through heterosexual sex.
Ms. Greer said a microbicide would be particularly useful for women from the aboriginal, African and Caribbean communities, who experience higher rates of HIV than the rest of the population. Women could protect themselves without their partner even knowing, she said, though she recommends that women always have conversations with their partners about protection before sex.