Research

What is Human Immunodeficiency Virus (HIV-1)?


HIV-1 is a virus that attacks the immune system in humans. It targets CD4 T cells (a type of immune cell) that are crucial for fighting off infections. If left untreated, the virus can impair the ability to fight off other infections and diseases. When the immune system is severely damaged (less than 200 CD4 T cells per microliter), this is clinically called AIDS. The graph above shows the relationship between the amount of virus (red line) and the numbers of CD4 T cells (blue line) over time. Initially, there is a sharp increase in virus levels at acute infection until immune responses begin to develop. However, since HIV-1 mutates extremely rapidly, there is an ongoing struggle to maintain control. Virus replication and loss of CD4 T cells can be controlled with the help of antiviral medications, known as cART, providing clinical management of the infection.

What is cART?

Combination Antiretroviral Therapy (cART) is the therapeutic treatment for HIV-1 infection. It consists of a combination of drugs of different classes that control HIV-1 virus replication. HIV-1 mutates so fast that one drug is currently not enough to manage the infection. Most patients take a combination of three drugs to minimize development of mutational resistance. If cART drugs are taken every day, it is possible to maintain very low virus levels and minimize loss of immune cells.


Current HIV-1 Therapeutic Drugs

  • To maintain viral suppression, adherence to cART drugs is required daily.
  • Even when HIV-1 is fully suppressed by cART, much of it still remains in the body in a dormant state, called the viral reservoir. Unfortunately, cART does not directly affect the viral reservoir. This is the source of virus when cART therapy is interrupted.
  • The lifetime cost of HIV-1 infection in the U.S. economy is estimated at over half a million dollars.
  • HIV-1 mutates so rapidly that therapies may need to be changed. This is especially important if treatment is interrupted.

Common Misconceptions

HIV-1 is still quite misunderstood throughout the world. Below are some common myths about the virus.

Myth: HIV can be spread through contact such as kissing, holding hands, or sharing utensils.

Fact: HIV is spread primarily through sexual contact and through blood. HIV does not transmit from saliva, sweat, or tears. The virus can sometimes be spread through childbirth or breastfeeding, but have become largely controlled. If a person has been taking antiretroviral drugs every day, the risk of spreading the virus is lower. HIV cannot be spread by mosquitoes.

Myth: HIV has stopped spreading.

Fact: While the rates of new HIV infections have declined over the last few decades, there are still millions of new cases of HIV every year.

Myth: Now that there are treatments for HIV, people don’t die from it anymore.

Fact: Medications have drastically increased the lifespans of many HIV-infected people, but not everyone has access to that care. Nearly half of HIV- infected people in the world still do not have access to the treatments that would save their lives. Without medication, HIV can quickly progress to AIDS.

Myth: HIV mostly impacts older people.

Fact: The largest proportion of new cases of HIV infection in the United States have been occurring in people between 13- 34 years old between 2010-2016 (CDC Feb 2019 Fact Sheet).

Myth: HIV is no longer a problem in the U.S.

Fact: While some countries have higher rates of HIV infection, the virus can be found anywhere in the world. HIV can have an impact anywhere that there are people, including the U.S.