A pill a day can keep HIV away...
To translate the scale of the HIV epidemic into a single measure: there are 4 500 new cases of HIV infection in the world each day. And Africa bears a disproportionate burden of the epidemic, accounting for about 70% of all people living with HIV.
South Africa, despite having just 0.7% of the world’s population, is home to about 20% (7.7 million people) of the global burden of HIV infection and a quarter million new cases in 2018.
Particularly concerning are the high rates of new HIV infection among adolescent girls and young women aged 15-24, with about 1 500 acquiring HIV every week.
In our country, adolescent girls and young women tend to acquire HIV infection at a much earlier age than their male peers. This age-sex disparity in infection rates is a consequence of girls partnering with men about 10 years older than them, and who may have recently acquired HIV or who are already living with HIV but are not on treatment with antiretroviral medicines.
When young women acquire HIV infection, they are more likely to drop out of school and run the added risk of exposing their unborn babies to HIV. Preventing new HIV infections among young women is the highest priority in the South African National Aids Plan.
In addition to the long-standing traditional ABCC prevention methods (abstinence, behavioural change for safer sex, male and female condoms and medical male circumcision), there is a new HIV prevention approach of “a pill a day”, referred to as pre-exposure prophylaxis (PrEP).
PrEP is a single blue tablet containing a combination of two antiretroviral medicines - tenofovir and emtricitabine - that has been shown in several clinical studies to be effective, when taken daily, in preventing HIV infection.
PrEP was first recommended by the World Health Organisation in 2015 as an additional prevention choice for people at risk of HIV. The South African Health Products Regulatory Authority approved PrEP in 2015 and the South African Department of Health first adopted this prevention approach with some restrictions in 2016.
The concept of PrEP is not unique to HIV; using effective treatment for prevention is widely applied in diseases such as malaria and tuberculosis. South Africans traveling to malaria transmission areas know well that they need to take the malaria treatment medication, Mefloquine, to ward off malaria.
For HIV prevention, the initial proof that antiretroviral drugs could prevent sexual transmission of HIV came from the Caprisa 004 tenofovir gel trial. Several subsequent studies testing the same antiretroviral but as a pill, demonstrated that PrEP was effective in preventing HIV. Ease of use, low cost, and high efficacy made the tenofovir-containing pills a better option than tenofovir gel.
The PrEP pill costs our government R754.55 a year (about R2 a day) at present. The two antiretroviral drugs in the PrEP pill have good safety profiles with few side effects.
Since PrEP is only needed when a person is at risk of HIV, it’s only required at certain times in a person’s life. For example, in the case of young women in South Africa, PrEP may only be required until they get married or settle down with an HIV-negative partner.
So PrEP is not something for a lifetime but for periods in a person’s life when they are at risk of HIV - unsure of their partner’s HIV status.
It’s important to note that the PrEP pill has to be taken every day during periods of risk to be effective.
A concern is that many of the people, especially young women in Africa, taking PrEP in the clinical studies were skipping doses and stopped taking the pills for several days. Poor adherence compromises the efficacy of PrEP and may also foster drug resistance.
In a programme where we made PrEP available to over a thousand men and women in urban and rural KwaZulu-Natal, we found that just over half initiated PrEP, and only two thirds of those were still taking it six months later.
This high drop-out rate in people at high risk of HIV is a concern not only in South Africa but in several other countries.
In a number of countries, PrEP implementation has drastically reduced the number of new HIV infections in high risk populations. For example, PrEP implementation in Australia was followed by a 35% decline in the number of new HIV diagnoses in men who have sex with men (MSM).
Similarly, new HIV cases in MSM in San Francisco in the US have declined by 47% following PrEP introduction and scale-up.
This success has unfortunately not been matched in women in Africa, where PrEP has not been implemented on a scale to make a real impact on HIV.
South Africa could change this. The Department of Health initially made PrEP available only to sex workers - which unfortunately tainted this HIV prevention approach in the eyes of some.
More recently, the health department has made PrEP widely available through government clinics, hospitals and university clinics. However, PrEP has been hesitantly introduced in South Africa. Currently there are about 34 000 people on PrEP in our country.
In contrast there are 56 000 people on PrEP in Kenya and 150 000 in the US, where PrEP is major part of the of the US government’s plan to end Aids there within 10 years and meet their UN ending-Aids targets in 2030.
In contrast, South Africa has not embraced the potential of PrEP as “a pill a day” strategy that could alter the course of the HIV epidemic in South Africa, if used widely with high adherence.
Unfortunately, not many people in our country are aware of this prevention option and very few are taking it. So why are more people not using PrEP?
First, many people, especially young people, don’t fully understand and acknowledge their personal risk of HIV.
Second, even those who appreciate their HIV risk may not know about PrEP or know where to obtain PrEP.
Third, there are those who start PrEP but are not able to take a pill every day, or take their pills only intermittently. Clearly, much more needs to be done to promote risk awareness, knowledge of PrEP and high pill adherence among those initiating PrEP.
As an affordable HIV prevention option, PrEP gives South Africa an opportunity to bolster its HIV prevention efforts and make a difference to its HIV epidemic. Now is the time to seize that opportunity with a-pill-a-day.
* Prof Salim S Abdool Karim is director of the Centre for the Aids Programme of Research in South Africa (Caprisa) based in Durban and Caprisa Professor of Global Health at the Mailman School of Public Health at Columbia University in the US. Quarraisha Abdool Karim is associate scientific director of Caprisa, the UNAids Special Ambassador for Adolescents and HIV, Professor in Clinical Epidemiology at the Mailman School of Public Health, Columbia University, US, and Pro-Vice Chancellor for African Health at UKZN