Here Jim Demarest delivers a very interesting TED Talk about the possible cure for HIV. Dr. Demarest is the Director of Microbiology Strategy at ViiV Healthcare, a HIV specialist company owned and created by GlaxoSmithKline and Pfizer. In this talk, he discusses the advances in the field of HIV treatment and management so far and also future perspectives.
Even though several infectious diseases are prevalent throughout the world, the number of deaths due to HIV is the highest. HIV indeed is the deadliest infectious disease in the world today. More than 35 million people are living with HIV globally. Dr. Demarest points out that although Africa is the worst affected region with the most number of people living with HIV, first world countries like USA and Western Europe also have a huge proportion of HIV-infected population.
HIV & AIDS
Dr. Demarest gives a brief introduction to the HIV virus and emphasizes on the difference between HIV and AIDS. He discusses both the mechanism of HIV replication and infection. HIV is a retrovirus and attacks only a type of white blood cell (WBCs) called CD4. Untreated HIV-infected cells become a factory where viral material replicates. These materials then go out and infect more CD4 cells. Eventually, infected cells start to die due to the infection. The ultimate stage of HIV infection is a state called Acquired Immune Deficiency Syndrome (AIDS). CD4 cells are of utmost importance in the immune system. Dr. Demarest demonstrates their importance by saying that they are like ‘the general of an army’ or ‘conductor of an orchestra’. CD4 cells manage and co-ordinate the immune responses of a body under various circumstances.
The first drug to treat HIV was AZT. AZT was introduced into the market for treating cancer. However, during laboratory analysis, scientists identified that growth of the HIV virus could also be impaired by using this drug. After clinical trials in March 1987, it was FDA approved. During that period, a number of drugs with the same mechanism came into the market. As research led to the elucidation of more information about the virus, 3 other drugs with mechanisms different from that of AZT were also introduced into the market. The introduction of the multitude of drugs into the market made doctors and scientists realize that only one drug wasn’t sufficient to control or eliminate the virus as it promptly develops resistance to the drugs through different mutations.
By 1996, a combination therapy was developed in order to deal with this issue. A combination of 2 or 3 drugs was used in a regime which not only slowed down the virus, but also restored the function of the immune system. Dr. Demarest showed published data proving this theory. He showed patient data demonstrating that the number of patients developing AIDS or facing death decreased drastically when combination therapy or HAART was introduced, .
Today different kinds of HIV drug regimens exist in the market. Most regimens are based on the concept of combination therapy and the introduction of 2-3 drugs combined in a single pill increases convenience and manages tolerability issues. Several patients are also considering stepping down from a 3-drug regimens to a 2-drug regimens after an initial period when the virus has already been controlled to save on cost and can be a more convenient option. Downgrading from a 3-drug regimen to a 2-drug regimen can also lead to better tolerability. Several clinical trials and experiments are being carried on for drug regimens that are cheaper, more convenient, more tolerable and at the same time highly potent.
A HIV drug regimen has to be followed very strictly for an entire lifetime for it to be effective but adherence is always a problem due to side-effects or psychological issues. Certain innovations like an injection or a patch treatment could potentially decrease the frequency of the treatment would be highly useful. This would also have a great positive effect on the psychological aspect of taking HIV medicines or treatment every day. Several collaborations among government, academics as well as industry are on-going to understand and develop these new advancements.
In spite of several prevention techniques and treatments available for HIV, significant amount of disease still exists out there in the world. Dr. Demarest raises the universal question of whether HIV can be cured? He discusses the cases of the Berlin patient, who became completely virus free after two bone transplants from an HIV resistant donor, and the Mississippi baby, who underwent a unique treatment post birth. These positive stories encouraged people to work towards a cure beause now it seems feasible.
Dr. Demarest says a cure can mean 2 different things – total eradication with no detection and no regrowth in the absence of therapy or a functional cure where a person could be HIV positive but can go off therapy without the regrowth of the virus.
Path to Cure HIV
The main problem in curing HIV is that latent HIV particles can stay in the body for years. They are persistent. Research has shown that latent infected cells might last for about more than 60 years. The key is to develop a technique to kill the cells expressing HIV without harming the uninfected cells and the patient. Applying anti-retroviral therapy in such scenario is being extensively researched on and is still in it’s early phase. Numerous collaborations are on going between virologists and immunologists to work towards developing a good delivery system using where the drug can be delivered directly to the site of infection.
Different organizations from all across the world, including patients, have joined hands to find a cure of HIV. 3 major initiatives are ongoing currently – one is funded by NIH, International AIDs Society is the second one and HIV forum for collaborative research (http://www.hivforum.org/) is the third. It brings great hope to the world to know that scientists from both academia and the industry are collaborating extensively and working together towards a path to cure HIV.