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 kill so many immune cells that the body is no longer able to fight off infections and diseases. When the immune system is severely damaged, this is called AIDS. The graph on the left 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 the beginning of infection (acute infection). As the body starts to fight the infection, virus levels decrease, but will steadily increase over time as CD4 T cells are gradually killed (blue line). As AIDS develops, the amount of virus sharply increases again, as there are so few immune cells left that there is nothing the body can do to stop this progression. However, the amount of virus and loss of CD4 T cells can be controlled with the help of antiviral medications.

What is cART?

Combination antiretroviral therapy (cART) is the method of treatment for HIV-1 infection. It consists of a combination of drugs that control HIV-1 virus replication in different ways. 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 make it unlikely the virus will become resistant to all of them. If these 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, a person has to take cART drugs every day. If doses are missed, the virus can quickly return and start killing T cells. This routine of taking medication every day has to be maintained throughout a person’s entire life.
  • Even when HIV-1 is suppressed by cART, a lot 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 ongoing 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 per person for drugs and regular clinical management.
  • HIV-1 mutates so rapidly that therapies may need to be changed. This is especially important if a person does not take their drugs on time.
  • People taking cART drugs may experience adverse effects. Side effects may include kidney damage, liver damage, serious psychiatric problems, bone density decrease, diarrhea, headaches and insomnia. These are discussed in more depth under the Impacts on Health page. Click the button below to directly access this page.

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. You can’t get HIV from saliva, sweat, or tears. The virus can sometimes be spread through childbirth or breastfeeding, but this has 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.