The National HIV/AIDS strategy for the United States states as it’s vision that “The United States will become a place where new HIV infections are rare, and when they do occur, every person, regardless of age, gender, race/ethnicity, sexual orientation, gender identity, or socioeconomic circumstance, will have unfettered access to high quality, life-extending care, free from stigma and discrimination.”
This would seem to be in line with the World Health Organization’s revised HIV guidelines that recommend that anyone who tests positive for the virus that causes AIDS should be treated immediately.
But what are those treatments?
In 1983, the Pasteur Institute in Paris isolated the AIDS virus. They used techniques learnt from the then emerging retro-virology field to do so. Further research indicated that the principal targets of HIV are immune cells, which help keep the body free from harmful foreign bodies. After entering the immune system the virus begins to replicate relentlessly. This spreads to other immune cells and the process results in devastation for the immune system.
Initial treatments proliferated. Many drugs were researched and produced. The first antiviral drug, zidovudine approved by the US Food and Drug Administration in 1986 acted to inhibit the enzyme HIV uses to synthesize DNA, thus preventing viral DNA from forming. There were also significant advances in the understanding of how HIV functions in the body, whittling away the body’s immune system right from the start.
The discovery that the HIV virus was becoming resistant to antiviral drugs and the development of many different classes of antiretrovirals led researchers and doctors to embark on combination therapy. Using combinations of antiretrovirals to fight the virus.
Now there are 30 anti-HIV drugs used in various combinations to treat HIV/AIDS, according to AIDS Research Alliance. A new strategy using various combinations of antiretrovirals has been to look at eradicating HIV reservoirs. HIV is able to remain a chronic, life-long infection due to its ability to stay hidden within infected blood cells. These cellular “reservoirs” contain the genetic code of HIV. They remain invisible to our body’s immune defenses, and are not sensitive to anti-HIV drugs.
These reservoirs of HIV are located throughout the body, including the brain, lymphoid tissue, bone marrow, and the genital tract. These reservoirs persist, even in the presence of Highly Active Antiretroviral Therapy (HAART), today’s standard of care. While HAART is able to deplete the reservoir, it does so very slowly. Mathematical models have shown that most patients would have to be on HAART for 60-80 years before their HIV reservoirs are depleted.
The only problem with antiretroviral drugs is that they have to be taken on a regular basis for them to remain effective. In less developed areas this may be a problem. Supply may be disrupted or the person may not be able to get to the doctor. A new antiretroviral drug called cabotegravir, however, may solve this widespread problem, since it only requires injection once every three months.
“Long-acting cabotegravir has the potential to create an option that could improve adherence by making it possible to receive the drug by injection once every three months,” explains Dr Martin Markowitz, a professor at Rockefeller University.
The innovation that has gone into this work has to be admired. It has been a long journey and as Dr Tom Ellman, director of the southern Africa medical unit for Médecins sans Frontières says “Nobody’s going to end AIDS with business as usual.”