Scientists return to HIV blocking gels for women

By Joe Ombuor

Even as scientists search for a vaccine that will protect a majority of people, microbicides have risen from their own string of setbacks to once again offer hope of preventing HIV infections.

The virus-blocking gels inserted into the vagina before sexual intercourse, say researchers, is out of its final bend headed for the homestretch is in the form of a ring to be worn by women. Women have borne the brunt of the killer virus.

Huge effect

Identifying a microbicide that works even partially could have a huge effect. Almost half of the more than 33 million people living with HIV worldwide are women and in sub-Saharan Africa, the figure is 60 per cent.

In many parts of the world, it is difficult for women to refuse sex or persuade a partner to use a condom. An effective microbicide would be something that women could initiate on their own.

The ring, similar to the ones widely used for contraception will be impregnated with anti-retroviral drugs and inserted into the birth canal to crash the virus at its raw stage.

Once proven safe and effective, vaginal microbicides could put the power of HIV protection in the hands of women around the world, potentially saving millions of lives.

These preventive drugs designed to counter infection before it takes hold come in gel, film and tablet form. Microbicides are meant to interfere with the virus before it inserts copies of its genetic material into a host cell’s DNA and begins replication.

Among the organisations involved in research on next generation microbicides based on ARV compounds is the International Partnership for Microbicides (IPM) that recently held a conference in Nairobi for researchers drawn from seven African countries.

IPM Chief Executive Officer Zeda Rosenberg describes the vaginal ring currently undergoing tests as the perfect revolution in the war against Aids.

Last 28 days

She says the ring designed to last 28 days once inserted, will empower women who often are vulnerable to infection due to biological, economic and social reasons. "Many women lack the power to insist their male partners use condoms or remain faithful. That is why HIV transmission is on the increase among married couples where abstinence is not an option. Women in marriage are also at risk of sexual violence," she says.

Ms Rosenberg says the next generation of microbicides being developed is a newer class of products based on the same classes of antiretroviral drugs being used to treat millions of people, already infected with HIV and to prevent mother to child transmission of HIV. "These next generation products are following the lead of treatment successfully adapted to life saving prevention methods for other diseases including malaria, influenza and pneumonia," she says. "Work is under way to identify the most promising ARV drugs that would be suitable for use as microbicides capable, of working in a variety of ways by either preventing the HIV virus from attaching to or entering a healthy human cell," she says. Candidates being studied include tenofovir and daprivine.

Research centres are at the Kenya Medical Research Institute in Kisumu and at International Centre for Reproductive Health in Mombasa. Other centres in East Africa are the Kilimanjaro Christian Medical centre in Moshi, Tanzania, and the Project Ubuzima in Kigali, Rwanda.