What is PrEP
PrEP stands for Pre-Exposure Prophylaxis. It is a daily drug that can be taken by people who don’t have HIV to prevent them from being infected with the virus. It can prevent HIV infection even if the virus enters the body through an exchange of sexual fluids or from an injection. There are many studies that confirm that PrEP prevents HIV infection from both hetero- and homosexual intercourse, as well as one study that suggests PrEP could also be effective for people who inject drugs.
To be effective, the drug must be taken every day in the same way that oral contraceptives are. PrEP should ideally be used alongside other protective methods, such as female and male condoms, as PrEP is not protective against other sexually transmitted infections nor is it a contraceptive. People who take PrEP need to get an HIV test regularly (currently around three monthly is recommended), as it is critical that HIV-positive people are not on PrEP (they need to move immediately onto anti-retrovirals). There are incidences of people becoming HIV positive whilst taking PrEP, however, in most cases these people had recently started PrEP and didn’t know they had just become infected. In some cases people were not consistently taking the drug and had low levels of PrEP in their blood samples. This highlights the importance of always getting an HIV test prior to starting PreP and also the need for adherence in optimising PrEP efficacy.
PrEP is absorbed differently in vaginal and rectal tissues, so there are different guidelines on how to take PrEP depending whether you have vaginal or rectal sex. PrEP is ten times higher in rectal tissues than vaginal tissues, therefore, If you receive vaginal sex you need to take PrEP every day for protection. If your HIV risk comes from anal sex, then there is more leniency on dosing (studies show 4 doses per week may be sufficient) and even dosing only at the time of sex is feasible (as shown in the ipergay study) . Essentially, this means that missing a dose is a bigger deal for women than it is for men who have sex with men.
PrEP does not need to be taken your entire life: only for the periods where you are at high risk of infection. The criteria for people at high risk are covered in the section ‘Who should take PrEP?’
How does it work
The original form of oral PrEP available is produced by Gilead and called Truvada®. Generic forms are available in South Africa. It is a combination of two HIV medications (tenofovir and emtricitabine). PrEP blocks the replication of the HIV virus in human cells thereby stopping infection.
PrEP does not prevent pregnancy or other sexually transmitted infections.
Who Should Take PrEP?
Who Should Take PrEP?
Anyone who is HIV negative can take PrEP, however, not everyone is at risk of an HIV infection. The following criteria are sufficient to request PrEP:
● A sexual partner who is HIV positive, not on ART or not yet virally suppressed.
● Sexually active in a high HIV prevalence population AND any of the following:
● Vaginal or anal intercourse without condoms with more than one partner, OR
● A sexual partner with one or more HIV risk factors, OR
● A history of an STI by lab testing or self-report or syndromic STI treatment, OR
● Any use of post-exposure prophylaxis (PEP), OR
● injecting shared needles, OR
● Breastfeeding from an HIV-positive person OR
● Requesting PrEP.
Example: PrEP should only be taken by HIV-negative people who either have an HIV-positive partner who is not virally suppressed OR who is sexually active in an area with a high HIV prevalence and engages in unprotected sex, has a sexual partner with HIV risk factors, has previously contracted an STI, or just feels it would be a good choice for them!
Generally, people who are at the highest risk of HIV infection include men who have sex with men, sex workers, and people who use drugs. These groups are known as key populations who bear a disproportionate rate of the HIV burden and find it difficult to access tailored services. In South Africa, as in much of sub-Saharan Africa, our high-risk key populations are additionally young women and adolescent girls. This is because the predominant way that HIV is transmitted in SA is through heterosexual intercourse. Many members of the general population are considered at high risk for HIV infection.
When was it made? How can I find it?
The Centre for Disease Control (CDC) approved PrEP in high-risk areas in 2014. As of 2017, PrEP is approved for HIV prevention by an increasing number of countries, including South Africa (the first country in Africa to do so). If you are in South Africa and interested in PrEP, phone the national AIDS helpline free of charge at: 0800 012 322.
If you don’t have access to PrEP or the drug isn’t right for you…
There are still plenty of ways to protect yourself from HIV infection.
● Using condoms (male or female) during sexual intercourse.
● Get tested and know your partners’ statuses.
● Limit your number of sexual partners
● Don’t inject drugs/use sterilised needles
● Encourage a positive partner to commence ART and to be virally suppressed.
What PrEP studies are ongoing at the Desmond Tutu HIV Foundation?
PrEP is rolled out and readily available in a few countries. It is gaining momentum in South Africa, but is not really available to the general public yet. However, it has the potential to be a powerful HIV prevention tool, so The Desmond Tutu HIV Foundation has many ongoing and upcoming studies looking at how acceptable and user-friendly PrEP will be within our communities.
3 P for PrEP
This project was designed for heterosexual adolescents girls and young women (15-24) who are sexually active. The 3P project recently launched in Cape Town and will deliver oral PrEP and HIV prevention advice to young people for one year. The main aim is to see whether giving young people an incentive may help young people “stick with” PrEP until the side effects disappear. A second aim is to see if current methods of generating interest in PrEP are working. Katherine Gill, who works on this study, said that “Our main aim of the study is to understand if a movie we made about PrEP was able to generate demand for PrEP.”
The power study focusses on young women, mostly between the ages of 16-22, and asks them about their perceptions of relationships and sex. It really gets down to why these women do and don’t take preventative medication against HIV. Generally, the women were enthusiastic about taking PrEP, but cited some off-putting factors including cost, side effects and ease of availability. The study is careful to emphasize that PrEP does not prevent pregnancy or other STIs.
The second stage of this study will be to offer PrEP to 1000 young women who will be enrolled using DTHF’s signature Tutu Teen Truck. This is a clinic-on-wheels that specialises in adolescent care and takes free healthcare to remote areas. Elzette Rousseau, who runs the study, hopes to “understand PrEP decision-making, …risk perception, fertility intentions,…and factors associated with discontinuation.”
Social studies will also be conducted to look into factors that influence decision-making around PrEP and PrEP adherence. The aim is to create PrEP distribution models for different socio-geographical contexts.
PrEP has great potential to reduce HIV transmission in young women if they show good adherence to the daily regimen. This study, which is still enrolling, will follow young women who are HIV-negative over a year and track their relationship with PrEP. For instance, it will look at reasons why they do or don’t want to take the drug and how it affects their relationships and sexual activity.
“All participants have the option to start using PrEP at enrollment,” notes Dr Sheetal Kassim who is running the study. Kassim adds that if participants refuse PrEP then they have the option to change their mind and start at any point. The researchers will be analysing why volunteers do or don’t want to take the drug and how it affects their relationships and sexual activity.
This study is aimed at men who have sex with men (MSM) who are a key population at high risk of being infected with HIV. MSM commonly face discrimination and barriers when accessing healthcare. It is an exciting opportunity to gather knowledge on commonly marginalised key populations in South Africa, and advocate for other PrEP options. This protocol compares oral Truvada®-based PrEP with a new injectable drug that could be another option for HIV-prevention, cabotegravir, given every 8 weeks.
This is the first time an ARV is being investigated both for treatment and prevention simultaneously. Participants will be randomly assigned to two arms and both groups will take a pill (either Truvada or placebo) and get two monthly injections (either Cabotegravir or placebo). The study also seeks to uncover whether people prefer to take daily pills, or whether an injection every two months is a better option.
Demystifying HIV Pre-Exposure Prophylaxis | Youreka Science
Written by Caroline Reid
Photo credit for feature image: NIAID Pre-Exposure Prophylaxis (PrEP) via photopin (license)