The battle with HIV goes on: how far along are we?
Writer: Adela Brzobohata
Editor: Haoyue Guo
Artist: Olivia Rani Bessant
The human immunodeficiency virus (HIV) has risen to fame in the beginning of the 20th century, claiming approximately 35 million human lives worldwide since then. HIV invades CD4+ T cells, which are essential for generating appropriate immune response. It uses these cells to replicate its genome and assemble new HIV virus particles. Ideally, by this point, one’s immune system would kick in and destroy the virus before it could spread into other cells. However, HIV has developed many strategies that undermine the immune response and allow it to live happily ever after in one’s body. For now. Throughout the course of HIV infection, the CD4+ T cell count gradually declines, as more cells get infected with HIV, causing gradual weakening of the immune system. Eventually, this leads to the last stop of HIV infection, acquired immune deficiency syndrome (AIDS), in which lethal opportunistic infections develop.
Tackling HIV has been, and still is, quite a pickle, yet highly effective treatments have been developed, which allow us to control the virus, slow down the progression of disease and reduce transmission. Most commonly, antiretroviral therapy (ART) involves an administration of different combinations of drugs, which target different viral activities, to patients. Plus, there are drugs that significantly lower one’s chance of getting HIV, if they are taken prior to exposure (PrEP) or soon after possible encounter of HIV (PEP). All these drugs so far managed to decrease HIV related deaths by between 60-80%. They can’t, however, cure the infection, so the hunt for an HIV vaccine and cure continues.
For viruses to survive, they need to transmit. Ideally, by putting every HIV positive person on ART and ensure that every unaffected person at risk of acquiring HIV infection takes PrEP/PEP, we could keep the viral load at levels which make transmission, and thus the survival of the virus, almost impossible. However, there are other factors that need to be considered. A huge stigma surrounding HIV discourages people to get tested and seek treatment if necessary; also, having to adhere to ART treatment everyday is highly inconvenient for patients, therefore the search for a cure and/or a vaccine must go on. So, is the future for an HIV cure bright?
Currently, only the two ‘chosen ones’, the former ‘Berlin patient’ and the latter ‘London patient’, who both suffered from HIV and a form of blood cancer resistant to chemotherapy, have been given a bone marrow transplant using stem cells from a healthy donor. Both donors possessed a rare mutation in the CCR5 gene, which codes for a receptor that allows HIV to attack white blood cells. Both patients have been free from HIV ever since.
Although the treatment might have been successful, it’s too expensive and risky to be used widely on HIV patients. Despite that, it did highlight new areas for research and provided novel insights into possible locations of the yet undetected HIV reservoir in the body – the haematopoietic system.
Once a prominent killer, HIV has now been imprisoned by the power of modern medicine and more people with HIV are able to live normal lives and less succumb to HIV related infections every year.
References
- Bhatti, A., Usman, M. and Kandi, V. (2016). Current Scenario of HIV/AIDS, Treatment Options, and Major Challenges with Compliance to Antiretroviral Therapy. Cureus, 8(3).
- Cdc.gov. (2019). PrEP | HIV Basics | HIV/AIDS | CDC. [online] Available at: https://www.cdc.gov/hiv/basics/prep.html [Accessed 16 Oct. 2019].
- German Advisory Committee Blood (2016). Human Immunodeficiency Virus (HIV). Transfusion Medicine and Hemotherapy, 43(3), pp.203-222.
- Warren, M. (2019). Second patient free of HIV after stem-cell therapy. Nature. [online] Available at: https://www.nature.com/articles/d41586-019-00798-3 [Accessed 19 Oct. 2019].
- Who.int. (2019). Why the HIV epidemic is not over. [online] Available at: https://www.who.int/hiv-aids/latest-news-and-events/why-the-hiv-epidemic-is-not-over [Accessed 25 Oct. 2019].
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