How does anti-HIV medication work — and would you use it?

It's one thing to have medicines available that can prevent people from getting infected with germs that lead to incurable diseases; getting folks to use those medications is another altogether. 

And it’s no different in the case of HIV. 

Over the past 12 years, ways to prevent yourself from contracting HIV have evolved from using condoms or abstaining from sex to taking medicines in the form of pills, injections and vaginal rings to block the virus from getting a foothold in the first place. This is called PrEP, short for pre-exposure prophylaxis.

The more choices there are, researchers say, the more likely people are to use at least one of them. This they learnt from contraception: studies show that contraceptive use increases when there are different methods to choose from. 

The daily HIV prevention pill was introduced to South African government clinics in 2016 — but far fewer people have used it than originally planned for. If taken daily, the pill can reduce your chances of getting HIV through sex to virtually zero. 

Researchers have learnt that one of the things we need to improve on when introducing new HIV prevention medications is to destigmatise it, so that the medicines are not thought of as being meant only for groups of people who have an especially high risk of getting HIV, such as sex workers, transgender women and men who have sex with men, but in fact for anyone who needs to lower their chances of getting infected. 

Implementation trials for an anti-HIV injection, which is taken once every two months, starts in South Africa this year so scientists can learn what would make people use the shot.

Infectious diseases specialist Linda-Gail Bekker of the Desmond Tutu Health Foundation at the University of Cape Town runs one of the trials. She spoke to Mia Malan on Bhekisisa’s TV programme, Health Beat.

Mia Malan (MM): When we started to use PrEP — the HIV prevention pill — in South Africa in 2016, uptake was pretty slow. Why was that?

Linda-Gail Bekker (LGB): When we started [rolling out PrEP] in 2016, the strategy was to make it available to what was considered key populations [for contracting HIV], for example, men who have sex with men and sex workers. That had two important implications: it stigmatised prevention and caused an “othering” attitude — the perception that “this is for other people, not for me”. 

MM: More options have become available for HIV prevention since then, and we now have three types of medication we can use. Can you just break them down for us? 

LGB: First, there’s the oral pill, which has two antiretrovirals in one tablet. You swallow one pill a day as protection against HIV. The second one is a vaginal ring. It’s made out of silicone and infused with an antiviral [drug] called dapivirine. You [or a health-care provider] insert it into the vagina, where it sits very comfortably at the top, right under the cervix [the neck of the womb]. Over the next 28 to 30 days, it slowly diffuses the antiviral, [delivering the drug] right there where the business happens. The third [option] is an injection that has to go into the butt [muscle]. Because it’s quite a large volume, it has to be given by a trained professional, every two months. So every eight weeks, you need to come in and get your next shot.

MM: The health department only distributes the pill at the moment, while the vaginal ring is still in implementation trials. But the pill seems to be more effective than the ring. So why would anyone then choose the ring?

LGB: Oral PrEP is highly effective in all populations, if taken as prescribed [meaning that you take one pill a day]. The difference between the ring and the pill is that the ring is topical (it is in the vagina), so very little of [the drug] gets absorbed systemically, which means there are very few side effects [in the rest of the body]. I think it’s going to come down to choice: do I want to swallow something daily, or do I prefer to use something that [sits on the outside and] I don’t actually have to take into [my] system? 

MM: Clinical trials have shown that the injection works better than the pill. We will be receiving some of these injections in South Africa for implementation trials over the next year. How will we know if people will actually use it?

LGB: That’s exactly what implementation studies are designed to do. Clinical trials tell us whether the product actually works or not. But then you have to [investigate] the real-world experience, putting it into clinics within the health system, with all of its ups and downs and in-betweens. Will people come [to get the product]? How many of them will prefer which one? Will they use it as prescribed? The implementation trial lets us do the real-world thing, but in a carefully monitored situation. 

MM: This injection is expensive, selling for around R70,000 per shot in the US. But ViiV Healthcare [the manufacturer] has announced recently that it will sell it at a nonprofit price of R540-R570 to countries like South Africa. But that is still too expensive for our health department because it’s far more than what the pill costs. So what now?

LGB: Affordability is important, but [we have to know that] it’s very expensive for young [people] to become infected with HIV, because then we [the public health system] need to provide them with antiretrovirals lifelong. Plus, it’s also about the cost of living with the virus. So [the question] is not just how much does it cost, but also how well does it work? How much is the value of saving someone from an infection, and therefore giving them a better handle on a healthy future? Having said that, we know that the price of these [products] comes down as we take things to scale. But before we get to that point, we’ve got to get the product into the country and use it. That may need donor funding, [such as from] Pepfar [the US President’s Emergency Plan for Aids Relief] or the Global Fund to get people to use these products, to understand what the value-add is to our country. I believe it will make a difference to our epidemic.

This story was produced by the Bhekisisa Centre for Health Journalism. Sign up for the newsletter.