HIV breakthrough

A South African husband and wife team have won the first-ever Olusegun Obasanjo Prize for their work on a microbicide gel that significantly reduces the risk of contracting HIV and genital herpes. Quarraisha and Salim Abdool Karim are epidemiologists with CAPRISA, the Centre for the AIDS Program of Research in South Africa. In 2007, they began a randomized medical trial of the effects of Tenofovir gel on HIV in women. The work was widely praised, voted one of the top ten scientific breakthroughs of 2010.

The experiment was populated by 889 healthy, sexually active women from Durban, South Africa, and the nearby community of Vulindlela. The group was divided in half, with one half given Tenofovir gel to be applied before and after sex and the other a placebo gel. Both groups of women were given HIV risk reduction counselling and condoms, and the researchers checked in monthly to assess adherence to the gel regimen.

The study ended in 2010. Results showed an overall 39 per cent reduction in HIV incidence in the group using the Tenofovir gel. Incidence in the most diligent users of the gel was even lower, a 54 per cent reduction compared to the placebo group. No serious side effects occurred as a result of using the gel.

KwaZulu-Natal, the province of South Africa where the study took place, has been hit harder by the HIV epidemic than any other area of the country. Women, especially young women, are disproportionately affected, and existing HIV prevention measures are underfunded and ineffective.

Studies into HIV prevention technologies have come up with little success, and almost none of them deal with technologies that can be used and controlled by women. “Women bear the brunt of the HIV epidemic in southern Africa. Tenofovir gel is the first HIV prevention technology to empower them to directly control their risk of HIV infection,” said Salim Abdool Karim. The gel is expected to be especially beneficial to women who are “unable to successfully negotiate mutual monogamy or condom use,” according to the paper published in Science last year.

Tenofovir was first tested as an HIV prevention measure in monkeys, and is currently available for oral use as tenofovir disoproxil fumarate, marketed as Viread, a drug that is widely used to treat HIV. It is long-lasting, effective at suppressing viruses, and relatively safe.

But don’t expect to see Tenofovir gel on the pharmacy shelves any time soon. “We got a proof of concept . . . Is it good enough? Absolutely not,” said Sharon Hillier, a reproductive scientist at the University of Pittsburgh. Hillier, who called the results “a really exciting first step,” is leading a study to replicate the Abdool Karims’ results.

The Abdool Karims were awarded the Olusegun Obasanjo Prize at a ceremony in Nairobi, Kenya, on Nov. 10. The prize, named after the former Nigerian president who funded it, is open to African scientists working in biotechnology, energy, information and communication technology, and material sciences. The winners are given a medal and a cash award of US$5,000.

This research could “alter the future trajectory of the HIV epidemic,” according to the African Academy of Sciences, who estimate that if Tenofovir gel becomes widely used it could avert as many as 1.3 million HIV infections and 800,000 AIDS deaths in South Africa alone.

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