Three Biomedical Interventions for HIV Prevention 

Treatment as Prevention (TasP)

Treatment as prevention is when people with HIV use antiretroviral therapy that makes HIV undetectable. It lowers the virus to less than 50 copies/milliliter of HIV in the blood so that there is effectively no risk of transmitting the virus. There is increasing evidence through HPTN-052, the PARTNER trial and the Opposites Attract study that indicates if a person with HIV is undetectable they will not spread the virus. However, the reality of using treatment as prevention as a tool is complex. People first need to know their HIV status, have regular access to health services and regularly take their medication. Below are two case studies that show its success and where it remains a challenge.

1. Case Study – Brazil: Brazil has been immensely successful in implementing TasP. In 1996, Brazil offered free antiretroviral therapy for all HIV positive people in the country. Making medications available to all has drastically reduced the spread of the virus within Brazil. According to WHO, 84 percent of the estimated 866,000 people living with the virus in Brazil knew they were positive. At least 75 percent are taking antiretrovirals. Furthermore, out of all the people on HIV treatment, 92 percent of them are undetectable. 
2. Case Study – Tanzania: Tanzania, on the other hand, has faced complex challenges with biomedical interventions for HIV. In sub-Saharan Africa, “girls and young women account for 74 percent of new HIV infections among adolescents.” Since 2007, the Elizabeth Glaser Pediatric AIDS Foundation (EGPAF) has funded the founding of “adherence clubs” to reinforce the importance of taking medication every day for young girls and women across Tanzania. These clubs, called Ariel Adherence Clubs (AAC), were implemented in six regions and 105 facilities within the country. The clubs are based around supporting HIV positive children ages five to 19 through their clinical needs while providing age-appropriate education and support groups to cater to their psycho-social needs. The study that evaluated the center found that viral suppression among the patients who attend the clubs was 60 percent versus 35 percent of adolescents who do not attend the clubs.

PrEP (Pre-exposure prophylaxis)

PrEP is used when a person who is HIV negative takes Truvada, an antiretroviral medication for HIV, to prevent transmission when exposed to HIV. Some have called PrEP the “plan B” of HIV. Although clinical studies such as iPrex, TD42, Fem-PrEP and VOICE have demonstrated the effectiveness of PrEP, real-world implementation has been a success for some countries and a major challenge for others.

1. Case Study – Thailand: Thailand has had one of the most successful adoptions of PrEP. In 2019, Thailand’s goal was to have almost 800 people on PrEP. There are currently an estimated 10,500 to 11,500 people on PrEP. One of the key factors in its success has been the diversity in types of support. A program named Princess PrEP was an initiative started in 2016 by Thai royalty to reach key vulnerable populations in the country. Sponsored by USAID, the initiative has aimed to have 1,000 people get on PrEP each year for three years. The program first targeted men who have sex with men (MSM) and transgender women, but it is now expanding to reach female sex workers and people who inject drugs. In 2018, the program focused on youth ages 15 to 19.
2. Case Study: the Philippines: The Philippines has lagged behind on the uptake of PrEP. According to PrEP Watch, the country has only had 100 to 300 people on the medication. Fortunately, in 2016, PrEP was introduced to the country through a demonstration project called PrEP Pilipinas. After the project ended, a local community organization, LoveYourself, started to offer PrEP in June 2019. It began an aggressive social media marketing campaign to educate the public about its benefits. Before access for the drug came to LoveYourself, the only way to get the medication was to travel to Bangkok.

PEP (Post-exposure prophylaxis)

PEP is an emergency response to a known or believed exposure to HIV within 72 hours. It can be used in an occupational setting for people who are exposed to bodily fluids during the workday or non-occupational setting. It is a medication that needs to be taken for 28 consecutive days to prevent the transmission of the virus.

PEP remains a challenge in many real-world settings. Despite the enormous amount of clinical trials that show that the regimen prevents HIV, uptake is low. When PEP is available, the regimen isn’t always fully completed, rendering the intended results uncertain or impossible. In 2014, WHO provided recommendations for the implementation and scale-up of PEP in low and middle-income countries. Below are examples of how countries have been successful or encountered challenges with implementing PEP.

1. Case study – Cameroon: From 2007 to 2016, the Yaoundé Central Hospital in Cameroon conducted an observational study. The hospital serves 11,000 people living with HIV. It was the first accredited HIV outpatient clinic and serves as a model for HIV management in the country. On a regular basis, the hospital staff counsels people coming in about occupational and non-occupational exposures to HIV about the uses of PEP. There were 300 people included in the study for non-occupational exposure. The highest number of cases was 75 percent who came in because they were sexually assaulted. Ten percent came in because a condom broke, and 15 percent came in because they had unprotected consensual sex. 
2. Case Study – Kenya: In Kenya, there have been particular challenges around adopting PEP among female sex workers (FSWs). Since 2009, the Kenyan AIDS Control Program has sponsored the availability of free PEP in designated clinics. Even with the availability of free medication, only 10 percent of FSWs attending the clinics used PEP. A 2016 study was conducted to evaluate the program and found that FSWs who were found to be at high risk are less likely to know about PEP, access PEP or finish the full course of the therapy despite the free resource. Therefore, in order for PEP to successfully prevent HIV among FSWs, it is necessary to provide education and counseling around the purpose and use of PEP.

Improving Access and Use of HIV Prevention Methods

Although challenges remain, several organizations and government programs have been funding and building up the capacity to scale up biomedical resources to prevent and treat HIV and AIDS in developing countries. These organizations and programs include the Bill and Melinda Gates Foundation, PEPFAR (President’s Emergency Plan For AIDS Relief), amfAR (The Foundation for AIDS Research), USAID (United States Agency for International Development), UNITAID (Accelerating innovation in global health), the Global Fund, Doctors without Borders, Columbia University’s ICAP and more.

These three biomedical interventions for HIV prevention can be accessible to all. With initial support from local governments, community organizations and global foundations, low to middle-income countries can develop sustainable programs and projects to provide TasP, PrEP and PEP to people who are vulnerable to contracting the virus.

– Danielle Barnes
Photo: Flickr