The Asia Pacific Conference on AIDS and Co-infection 2021 (APACC2021) was recently held online. During the meeting, the president of the general assembly, dr Nittaya Phanuphak, shared a report on "translating the science of long-acting prep into implementation". Hepatology digest interviewed dr Nittaya Phanuphak on this topic.
What is the clinical definition of PrEP applied to HIV? What are the corresponding HIV high-risk intervention groups?
Dr Phanuphak: Basically, pre-exposure prophylaxis of PrEP for HIV is a combination of two anti-retroviral drugs given to HIV-uninfected/ HIV-negative individuals to prevent HIV. You will see various definitions of how you define people at risk for HIV infection who would be eligible for PrEP in different guidelines. For example, for Thailand, we define those who are at risk as people who have high-risk behavior, not those who are in certain populations. People with high-risk behaviors include everyone regardless of gender or the population or community they are in. Anyone who has condomless sex, anyone with a history of sexually transmitted infections, anyone who shares injecting equipment with others, or those who come asking for post-exposure prophylaxis meaning they have problems using condoms, are the people we would consider eligible for PrEP by having high-risk behaviors. We have one last criterion of people who actually come in and ask for PrEP, meaning they may not have had high-risk behaviors before, but they know that they will be involved in risky behavior in the near future. So you will see that we are not saying that if you are a gay man, you should use PrEP, or if you are a drug user, you can access PrEP. No. We are saying that anyone with high-risk behaviors can come in for PrEP.
In combination with the guidelines, would you please talk about what are the representative PREP programs at present? Which groups are they suitable for?
Dr Phanuphak: As I mentioned, we do not use population groups in PrEP guidelines. We use risk behaviors for eligibility in PrEP guidelines. However, in terms of implementation, it is very important that we know who will be a target client so you can design service delivery to fit their contextual lifestyle. In each country, you may have different key populations. In many countries in the Asia-Pacific region right now, almost half of our new HIV cases each year are happening amongst men who have sex with men and transgender women. In certain countries, the proportion can be as high as 80% of new infections. This explains how each country prepares its services for men who have sex with men and for transgender women. In a few countries where people using and injecting drugs are the key population, such as in Myanmar and Vietnam, you will see that PrEP programs are adapting themselves to be ready to provide service in a friendly and non-judgmental way. So I would say that men who have sex with men and transgender women, sex workers and people who use and inject drugs are the key populations here.
What is the preventive effect and safety of PrEP? Would you please share in detail with recent or latest clinical research data?
Dr Phanuphak: We can say that in real life we have seen the effectiveness of PrEP in preventing HIV by more than 99%. Here that is true for all populations that we have already mentioned that are at risk for HIV because of their sexual behavior and those who have a risk for getting HIV beyond sexual risk such as injecting risk as well. When I say we have seen this in the real life setting, I mean that right now, we have more than one million people globally who are taking oral PrEP to prevent HIV. So far, I believe we have seen only seven people who have failed on PrEP, meaning they are taking PrEP correctly with high adherence and adequate PrEP levels in their body compartments, but still acquire HIV. That could be explained by acquiring HIV because of developing resistance to the medication that we are now using. So that reflects the general effectiveness of PrEP in real life. Some of you will have read some articles around randomized controlled trials in PrEP in different populations, and you will have seen that different numbers are being cited. For example, among men who have sex with men, an efficacy of 42% has been reported, but this is a different number because in a randomized controlled trial, people do not know if they were given placebo or the oral TDF/FTC (PrEP), and the efficacy number from each clinical trial actually reflected the level of adherence that participants in those studies were having during the study period. So in a study with a high level of adherence, there will be a higher efficacy number. In a study with less adherence accuracy, there will be a lower efficacy number. But in real life, as I mentioned, we have seen more than 99% efficacy because these are people who know they are taking oral TDF/FTC and taking it with the highest adherence that they can in real life.
What are the advantages and disadvantages of PrEP compared to other HIV prevention methods? What is the outlook?
Dr Phanuphak: Many people are looking at PrEP as an alternative strategy for HIV prevention, but I would say that in reality in practice, we are using PrEP as part of a combination HIV prevention package. In the past, you only had the option to abstain from sex to prevent HIV, and use condoms and lubricants to prevent contracting HIV, but now we are adding PrEP as another option in that package that you can choose from. People who use PrEP will probably not PrEP for the rest of their lives. There will be a certain period in their lives when they feel they are not at risk anymore and they can stop PrEP or use condoms and do not need to continue with PrEP every day, for example. These are options that you can choose from one combination package. Maybe people should still use PrEP together with condoms to enhance confidence when having sex. Many people who cannot use condoms well now choose PrEP as their main protective measure in terms of HIV. They may be able to use condoms from time to time depending on the sexual context during that time period. You can see that these options for people to choose from are increasing access for people who are coming in for HIV prevention. It is very similar to family planning options - the more options you have, the higher number of women will be protected from an unplanned pregnancy. The more options there are in HIV prevention, the greater the number of people who will be protected from HIV. By saying this though, this only applies to prevention of HIV infection. It does not apply for prevention of pregnancy or the prevention of other sexually transmitted infections. What we have to know is that when we are talking about PrEP, we are saying that for HIV prevention, PrEP is the best prevention measure for HIV because it provides more than 99% protection compared to condoms which give 70-90% protection for HIV. Is PrEP the best measure to prevent STIs? No. PrEP is only effective for HIV. Condoms will still be the best prevention measure to prevent HIV and other STIs as well as pregnancy.
Apart from the intervention of PrEP, is it necessary to take other HIV prevention measures? If necessary, what are the auxiliary measures?
Dr Phanuphak: That’s a very good question. As I have said, if your concern is HIV, PrEP is the best prevention method for you. But by taking PrEP, that does not mean you can just rely on it alone. You should still do HIV testing to make sure you are HIV-uninfected before you start PrEP, because there is a risk that people who have HIV who start PrEP can develop resistance to HIV. As we know, PrEP contains two anti-retroviral drugs which can suppress but not treat HIV for a long time. To test regularly for other sexually transmitted infections is another important measure that is part of this PrEP service. You cannot just take PrEP without coming in regularly for HIV and STI testing. Then, as has been mentioned, if you are also concerned about other sexually transmitted infections and pregnancy, then condoms and lubricants will still be the main measures for you to use together with PrEP. I would also say that being part of a sexual health service and coming in for checkups is giving you and society the test-and-treat effect. When we see more people coming in more frequently for STI testing, we identify more syphilis, more gonorrhea and be able to treat those conditions, which did not otherwise become visible to us as healthcare providers before PrEP, because these people would not have come into the health service for any other purpose. At the same time, taking PrEP will give you the opportunity to have other STIs screened and treated, as well as giving the opportunity to access other vaccinations as prevention methods for those STIs that can be prevented using vaccines. For example, hepatitis B, which is very common in our region, can be screened for. If you don’t have immunity to hepatitis B, you can be vaccinated. Human papilloma virus (HPV) is also very common amongst men who have sex with men and transgender women, and there is the HPV vaccination that can be given as part of the sexual health service.
What strategies have been adopted in the practice and promotion of PrEP? What are the challenges and unsolved problems?
Dr Phanuphak: I think that is a great question. I would answer it using our experience in Thailand, as well as experience in Vietnam and the Philippines. I mention these three countries because in the Asia-Pacific, these are the three countries with the highest numbers of people accessing PrEP so far (not counting Australia). These countries are places where we have been more successful than others with PrEP programs and where we are doing well already. In Thailand, for example, we calculated the number of people who would need PrEP to end HIV here, and that number was 140000 people. But over the past six years that we have had PrEP programs in our country, we were only able to get 10000 people on PrEP (<10% of the people who might benefit from PrEP). The main reasons are the challenges for people at risk for HIV to access clinics to get PrEP, because these are people who are so vulnerable through their sexual or gender identity, their drug use status, their sex work status. It is not easy for these people to just walk into the hospital and ask for PrEP. That is from the client’s side. From the provider’s side, at least in Thailand, we have asked hundreds of hospitals to act as outlets for the service, but less than thirty have declared they are ready to do so because their healthcare providers may not feel comfortable enough to give drugs to people who are not infected with HIV. They are comfortable treating HIV patients, but not to give drugs to HIV-uninfected individuals. There are judgmental attitudes and stigma discriminations surrounding PrEP services. The solution that Thailand, Vietnam and the Philippines have taken is to use the key population-led health services. This is something that is important to include for your readers. Key population-led health services (KPLHS) is a concept where key populations themselves, for instance, gay people, design the service they would like to use and then co-deliver the service and be part of the service in the clinic. They speak the same language – gay language, transgender language, sex worker language. This key population-led health service model has been the key facilitator of getting more and more people to come in for PrEP services. In Thailand, 70% of PrEP clients are using PrEP services through these key population-led clinics. Same as in Vietnam. There may be a higher number in the Philippines.
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