HIV infection continues to be a major public health issue in the United States, according to the Centers for Disease Control and Prevention (CDC). Recent data show that the vast majority of new infections among women are attributed to heterosexual contact.¹

Findings from a new study, conducted in the KwaZulu-Natal province of South Africa, indicate that genital inflammation lowers the effectiveness of tenofovir gel in preventing HIV infection in women.² Data from the study, conducted by researchers at the Centre for the AIDS Programme in Research in South Africa (CAPRISA) and Columbia University’s Mailman School of Public Health, suggest that both genital inflammation and adherence need to be addressed to increase the effectiveness of topical pre-exposure prophylaxis strategies [PrEP] for HIV prevention in women.

The study offers researchers an important clue to enhance HIV prevention in women, notes Salim Abdool Karim, PhD, CAPRISA director and professor of epidemiology at Columbia’s Mailman School of Public Health.

“It is not only adherence-related behaviors, but also biological processes in the vagina, that need to be addressed to prevent HIV and enhance the effectiveness of topical pre-exposure prophylaxis,” said Karim in a press statement.

To perform the analysis, researchers looked at HIV infection rates and cytokine levels as a marker of genital inflammation in 774 women over 2.5 years. The analysis indicates that women with genital inflammation were at higher risk of subsequently contracting HIV compared to women without inflammation. Application of tenofovir gel provided 57% pro-tection against HIV acquisition in women who had no evidence of vaginal inflammation, but provided no protection in women with genital inflammation, even if they used the gel consistently, researchers say.²

What’s the next step? According to Jo-Ann Passmore, PhD, professor at the University of Cape Town and principal investigator of the study, researchers plan to expand their results to assess how genital inflammation may affect the efficacy in HIV prevention trials of vaccines, passive immunization with antibodies, and antiretroviral PrEP administered through pills, rings, and implants.

Check MEC Guidance

There continues to be evidence of a possible increased risk of acquiring HIV among progestin-only injectable users; scientists are unsure whether this is due to methodological issues with the evidence or a real biological effect.³ In 2017, the CDC issued an update to its U.S. Medical Eligibility Criteria for Contraceptive Use, 2016, revising its recommendation on the use of the progestin-only contraception injection DMPA (depot medroxyprogesterone acetate) by women at high risk for HIV from Category 1 (no restriction) to Category 2 (benefits outweigh theoretical or proven risks).⁴

The guidance indicates that women at high risk for HIV should continue to have access to the contraceptive shot, but should be counseled about a possible, but uncertain, increased risk of getting HIV and how to reduce their risk. Clinicians should strongly encourage HIV infection prevention measures, including limiting the number of sexual partners, correct and consistent use of condoms, and consideration of preexposure and postexposure prophylaxis, for all women at risk for HIV acquisition.⁴

Researchers now are conducting the first randomized clinical trial designed to assess the risk of HIV acquisition by women using one of three contraceptives: DMPA, the levonorgestrel implant Jadelle, and the copper IUD. The ECHO Study (Evidence for Contraceptive Options and HIV Outcomes) was launched in December 2015. Spread across 12 research sites in Kenya, South Africa, Swaziland, and Zambia, the study also is designed to evaluate the performance of these methods in relation to pregnancy rates, side effects, and women’s patterns of use. Initial results are expected in early 2019.

A potential new option may offer women protection. Interim results from a study in which all participants are offered use of a monthly vaginal ring containing dapivirine, an antiretroviral drug, indicate that women’s risk of acquiring HIV is reduced by more than half with use of the device.⁵

The monthly ring, developed by the nonprofit International Partnership for Microbicides, is currently under regulatory review in Europe. It is designed to provide women with a discreet and long-acting HIV prevention option. The Partnership also is developing a three-month dapivirine-only ring to offer women increased convenience and reduce annual costs, as well as a three-month dapivirine-contraceptive ring to offer both HIV prevention and contraception. Both rings entered first clinical trials in 2017. 

REFERENCES

1. Centers for Disease Control and Prevention. HIV Surveillance Report, 2015; Available at: http://bit.ly/2gTB1iZ. Accessed March 16, 2018.
2. McKinnon LR, Liebenberg LJ, Yende-Zuma N, et al. Genital inflammation undermines the effectiveness of tenofovir gel in preventing HIV acquisition in women. Nat Med 2018; doi: 10.1038/nm.4506. [Epub ahead of print].
3. Polis CB, Curtis KM, Hannaford PC, et al. An updated systematic review of epidemiological evidence on hormonal contraceptive methods and HIV acquisition in women. AIDS 2016;30:2665-2683.
4. Tepper NK, Krashin JW, Curtis KM, et al. Update to CDC’s U.S. Medical Eligibility Criteria for Contraceptive Use, 2016: Revised recommendations for the use of hormonal contraception among women at high risk for HIV infection. MMWR Morb Mortal Wkly Rep 2017;66:990-994.
5. Baeten J, Palanee-Phillips T, Mgodi N, et al. High uptake and reduced HIV-1 incidence in an open-label trial of the dapivirine ring. Presented at the 2018 Conference on Retroviruses and Opportunistic Infections; March 2018.