How AIDS Works

World Impact of AIDS
Indian students carry signs during an AIDS awareness demonstration in Amritsar.
Indian students carry signs during an AIDS awareness demonstration in Amritsar.

In the years after the discovery and identification of HIV/AIDS, the syndrome was a terrible killer. Early treatments sometimes proved nearly as damaging as the disease itself. But starting in the mid-1990s, doctors began using a new treatment regimen that involved deploying an antiretroviral "cocktail" of several drugs simultaneously. The cocktail, called Antiretroviral Therapy, or ART, can't cure AIDS; rather, it controls viral replication, allowing the immune system to recover and strengthen. ART has turned out to be remarkably effective, transforming AIDS from a death sentence into a survivable and manageable disease. In fact, a person living with HIV who receives good treatment and lives a healthy lifestyle might live as long as a person without the virus [source: The Body].

Three million people were dying of AIDS every year in 2005, but 10 years later that number has dropped to 1.2 million. As of 2015, the number of people living with HIV remains relatively steady at 37 million, but the number of new infections has dropped from 4.9 million to 2 million per year in the same period [source: WHO].

However, current treatments are less than ideal. ART can have long-term side effects such as chronic inflammation leading to organ damage and premature aging [source: Groopman]. It's also expensive, making it difficult to extend treatment to low-income people in general or to people in countries with underdeveloped medical infrastructures. Because the majority of AIDS cases persist in some of the world's poorest countries, this is a serious problem.

According to WHO, of the 37 million people estimated to be living with HIV as of 2015, only 15 million had received antiretroviral therapy. Another factor is that researchers estimate only 51 percent of people with HIV are actually aware of their status [source: WHO].

HIV is a latent virus, meaning that not only can it lie dormant for years before developing into full-blown AIDS, but it can also go into hiding when a patient is receiving treatment. This makes it incredibly difficult to eradicate. In fact, only one person in the world is known to have been fully cured of HIV. Scientists are studying his case to better understand how a cure might be effected.

The key, it seems, will be to develop a safe and affordable way of eradicating the viral reservoir that can lie dormant, unfazed by ART. Approaching the problem from multiple angles, some researchers are looking for ways to use the body's immune system to do the job; some are experimenting with genetically engineered stem cells; and others are developing "shock and kill" drug therapies. All are optimistic that AIDS can eventually be cured outright, with one researcher suggesting this could happen within 10 to 20 years [source: Groopman].

Prevention, as they say, is the best medicine. Those who are at a high risk of contracting HIV/AIDS can take a pill called pre-exposure prophylaxis, or PrEP, which combines two types of medications. When taken consistently every day, PrEP can reduce the risk of HIV infection by 92 percent [source: CDC].

Meanwhile, the search for an AIDS vaccine is ongoing. In 2015, Michael Farzan, an infectious disease specialist at the Scripps Research Institute in Florida, announced a promising new possibility.

Structurally, HIV has spikes called glycoproteins, each equipped with two sites that attach to immune cells. Farzan described a compound that prompts muscles to produce a special protein that, unlike most antibodies, has both a head and a tail. The head of the protein blocks one site on an HIV spike, and the tail blocks the other, making it impossible for the virus to attach to an immune cell. Deprived of a home, the virus wanders off and is eventually destroyed by the immune system. So far, four monkeys have been completely protected against repeated exposure to HIV for a year [source: -McNeil].

In September 2015, the Scripps Research Institute announced that the Bill & Melinda Gates Foundation had given Farzan $6 million to develop his compound into an HIV vaccine for humans [source: Scripps].