Dr. Salim Abdool Karim,
CAPRISA director and NIH
grantee, recently spoke at
NIH on "Envisioning the
End of AIDS."
Q and A with Dr Salim Abdool Karim of CAPRISA
Dr. Salim Abdool Karim is a clinical infectious disease epidemiologist and world expert in HIV prevention and treatment research. He directs the Center for the AIDS Program of Research in South Africa (CAPRISA) and is a grantee of the National Institute of Allergy and Infectious Diseases (NIAID) and Fogarty. He recently stepped down as President of the South African Medical Research Council (MRC) to focus more on his research. His academic affiliations include the University of KwaZulu-Natal, Columbia, Cornell, MIT and Harvard. Below are excerpts from his recent lecture at NIH.
What progress has been made against HIV?
What we are seeing now is a different phase of the HIV epidemic than the first 25 years. We've seen a huge push and increase in resources to fight AIDS. Several countries are systematically closing the gap between those who should be on treatment and those who actually are on treatment. If we look at the expenditure by each of the key countries, we see rapid growth in local expenditure in the last several years at the country level. So now we are no longer seeing the same level of dependence on international assistance, we are seeing countries rising to the challenge of treating their people with local financial resources. We have seen antiretroviral treatment (ART) having a dramatic impact at the community level, increasing life expectancy by as much as 20 percent in some instances. There's no other intervention in history I can think of - maybe the steam engine, introduction of clean water and sanitation or the agricultural revolution - that led to such enormous increases of life expectancy. And at the same time, we're seeing the benefits of prevention. But we still have much work to do.
What are the biggest challenges?
We already have 35 million people living with HIV with no cure in sight, so AIDS is not going away anytime soon. Even as we start talking about the end of AIDS, it's a substantial existing problem affecting almost every region of the world. We have not yet controlled HIV globally due to a range of obstacles, with three of them being key. The first is dysfunctional health systems. While we have new efficacious tools to fight HIV, we have not been always able to convert them into prevention interventions with maximum effectiveness. Second, although the number of new infections is going down globally, HIV continues to grow in several key populations such as young women in Africa, men who have sex with men, transgender persons and injecting drug users. And then the third is stigma and discrimination, which remain major obstacles to both treatment and prevention access.
What role should research play?
A key step on the path to ending AIDS is what I call epidemic control. We're talking about that point at which AIDS no longer represents a public health threat, which can be mathematically defined as a reproductive rate of HIV infection that is below one. We're not going to get there unless we really know our local epidemic, the key populations and the detail of the local epidemiology that defines where the pockets of populations with ongoing high HIV incidence continue to exist, that are recalcitrant, that are not being impacted by our overall large-scale intervention. We've got to target those pockets. We need to find those key populations because their high incidence sustains the epidemic in those countries. We've got to deal with the underlying drivers of HIV vulnerability. We cannot deal with the problem of high HIV rates in sex workers if sex work is illegal and driven underground. We cannot deal with the challenges of implementing HIV prevention tools in men who have sex with men in Uganda if imprisonment is what they face. It's going to take the kind of global solidarity that raised billions of dollars to fund the anti-AIDS effort to now also deal with these kinds of legal, social and structural obstacles to HIV prevention and treatment. And it is going to take new innovations and technologies.
What innovations are needed most?
To reach the goal of scaling up antiretroviral treatment to everyone with HIV, we need a new paradigm for the way in which these services are provided, especially in high burden settings. In a country like South Africa, with six million people living with HIV, if we are to make treatment available by the current approach - where patients have to take a tablet every day and come to the hospital or clinic regularly to get their blood tested and get their next set of tablets - I think we are in a situation where the already over-burdened health system will simply not cope. I foresee a day where HIV patients who have undetectable viral loads could be switched to four injections a year with new long-acting antiretroviral drugs that are currently being tested. In the future we may even have therapeutic antibodies to further supplement antiretroviral treatment, where viral loads are no longer being checked in the laboratory but where you have a simple little gadget that fits onto your cellphone and you can check your viral load every few months. These are the kinds of innovations that will make the target of treating all HIV-positive patients, for both therapeutic and prevention benefits, a realistic one because they will enable the health services in developing countries to provide treatment sustainably.
Also, we're going to have to find new diagnostics for primary HIV infection. This remains an ongoing problem, where we are putting patients on treatment several years after they've become infected and have already spread the virus to several people. And we've got to look at new approaches for prophylaxis - longer acting formulations with either antiretroviral drugs or immunoprophylaxis. I am hopeful that current research on broadly neutralizing antibody will enable us to find a combination of these antibodies that will be effective as a long-acting injectable or topical prophylaxis, as an interim solution while the search for a vaccine for active immunization continues.
Finally, we need an implementation science agenda that really helps us understand what it's going to take to get healthy people, both HIV-positive and -negative, to interact with the health service. One of our big challenges in the scale-up of treatment is retention in care with high adherence, especially in those HIV-positive patients who are feeling well. Similarly, we have a challenge in attaining high adherence to current prophylactic approaches like condoms and oral pre-exposure prophylaxis. We have to find innovative ways of caring for healthy people, ways in which they don't have to physically go to the health service but the health service is able to effectively reach out to them and provide them with treatment or prophylaxis in a way that works best for them.
We risk losing the momentum against AIDS if we miss this historic tipping point created by an amazing amount of research we've seen in the last four years. Achieving epidemic control depends on doing what we know works. We can't simply be doing great science to find and discover new tools. We're going to have to do great science to figure out how to get those tools to the people who need them so that we see their impact. I don't believe we're going to end AIDS tomorrow, but I do believe that objective has to be part of our long-term vision.