Bill & Melinda Gates Foundation funds UCSF research to test diaphragms as HIV prevention tool

The Bill & Melinda Gates Foundation has awarded $28 million to test whether the diaphragm can prevent the transmission of HIV, to UCSF’s Women’s Global Health Imperative (WGHI), directed by Nancy Padian, PhD. The diaphragm will be the first physical barrier tested in a randomized, controlled trial for effectiveness in preventing the sexual transmission of HIV.

“The foundation is demonstrating tremendous leadership and innovation in supporting research to examine women-controlled HIV prevention methods. Their foresight could potentially save many lives,” said Padian, who is also UCSF professor of obstetrics, gynecology, and reproductive science, and director of international programs at UCSF’s AIDS Research Institute (ARI). The study will enroll 4500 women at two sites in South Africa and one in Zimbabwe.

Because many people are skeptical that women would use the diaphragm, Padian first conducted an acceptability study among women in Zimbabwe, where close to a third of the population is infected with HIV.

“We asked women whose partners would not consistently use condoms if they would try using the diaphragm, even though we told them we did not know if it could prevent disease.  Their enthusiasm to use a product that did not require negotiating with their male partner was overwhelming.” said Padian.

Because it protects the cervix, the diaphragm holds enormous promise for preventing HIV transmission.  The cervix is a “hot spot” in terms of susceptibility to HIV infection and other sexually transmitted diseases (STDs), and the majority of infections most likely occur there. The surface of the cervix is very thin and fragile whereas the vaginal walls are much thicker.  The cervix also has more cells with HIV specific receptor sites than the vagina.

In addition, contractions of the uterus aspirate or draw fluids up into the upper genital track, which has also been shown to be very susceptible to HIV and STDs. Physical protection of the cervix would block this transport of fluids.

“South African medical ethicist Solomon Benatar observed that acquiring new scientific knowledge is often valued more than applying existing knowledge. Thus he urges that we explore existing options as part of our HIV prevention strategy. The diaphragm, here and ready now, is precisely such an option. Diaphragms are already approved for use as a contraceptive and purchasable in most countries.  A positive outcome from this study could rapidly put an urgently needed female-controlled HIV prevention technology into the hands of women throughout the world who are at risk for HIV,” said Padian.

“In the past 5-10 years UCSF has become an important player in global health.  Dr. Padian has been on the forefront in this endeavor and her program on HIV-AIDS prevention in Zimbabwe is a primary example,” said Haile T. Debas, MD, dean of the UCSF School of Medicine and Vice Chancellor for Medical Affairs.

WGHI is a global research program based at UCSF’s AIDS Research Institute and UCSF’s department of obstetrics, gynecology and reproductive sciences.  Scientists at WGHI conduct research and training related to HIV/AIDS, gender and reproductive health.

This research is used to design and rapidly implement practical and effective prevention and treatment strategies for women at risk for or living with HIV. ARI houses hundreds of scientists and dozens of programs throughout UCSF and affiliated labs and institutions, making ARI one of the largest AIDS research entities in the world.