HIV Overview

All vaccines “teach” our immune system to recognize and effectively defend our bodies against viruses or bacteria. Examples of existing vaccines are polio, tetanus, and measles. When available, a preventive HIV vaccine will be given to people who do not have HIV, with the goal of preventing HIV infection if they are exposed to the virus. A preventive HIV vaccine will teach our immune system to protect against HIV in case we are ever exposed to the virus.

After almost four decades of research, there are currently no U.S. Food and Drug Administration (FDA)-approved preventive HIV vaccines. However, scientists are pursuing innovative strategies to design an HIV vaccine to prevent or to treat HIV infection. You must be enrolled in a clinical trial to receive an experimental HIV vaccine (see more details below).

The goal of a preventive HIV vaccine is to prevent people from getting HIV. When available, it will be given to people who do not have HIV.

A therapeutic HIV vaccine is for people who already have HIV. The goal of a therapeutic HIV vaccine is to strengthen the natural immune response to the virus that is already in people with HIV.

Researchers are exploring the use of therapeutic HIV vaccines to:

• Slow  the progression of HIV infection in people with HIV.
• Achieve HIV remission, also called a functional cure (keeping viral load suppressed without the need for antiretroviral therapy [ART]).

To learn more, read the HIVinfo What is a Therapeutic HIV Vaccine? fact sheet.

No, a person cannot get HIV from a preventive HIV vaccine. The preventive HIV vaccines being studied in clinical trials do not contain HIV. Each vaccine being tested uses a slightly different design or strategy but none of them can actually transmit HIV. Of the approximately 30,000 people who have participated in HIV vaccine studies around the world in the last 25 years, no one has gotten HIV from any of the vaccines tested.

Treatment options for HIV have improved a lot over the last 30 years. However, like most other medicines, HIV medicines can have side effects, can be expensive, and can be hard to access in some countries. Also, some people may develop drug resistance to certain HIV medicines and then must change to different medicines.

Using condoms correctly every time and taking pre-exposure prophylaxis (PrEP) can help prevent HIV transmission.

Researchers believe a preventive HIV vaccine will be the most effective way to control or completely eliminate new HIV infections.

Some of the areas of interest being studied in clinical trials include:

• The safety of preventive vaccines.
• Whether a preventive vaccine protects against HIV infection.
• Whether a preventive vaccine controls HIV if a person gets HIV while enrolled in a study. Participants can get HIV through sexual contact or from sharing drug injection equipment while they are participating in a clinical trial. As stated above, a person cannot get HIV from the HIV vaccine being tested.
• The immune responses that occur in people who receive a preventive vaccine.
• Different ways of giving preventive vaccines, such as using a needle and syringe versus a needle-free device.

An online database of clinical trials on preventive HIV vaccines is available from the ClinicalTrials.gov study summaries. Click on the title of any trial in the list to see more information about the study.

If you are interested in participating in a vaccine study, you can also contact the National Institutes of Health Vaccine Research Center by calling 866-833-LIFE (5433) or by emailing vaccines@nih.gov.

To learn more, read the HIVinfo fact sheet on HIV and AIDS Clinical Trials.

From the National Institute of Allergy and Infectious Diseases:

• HIV Vaccine Development

From the HIV Vaccine Trials Network (HVTN):

• How Vaccines Work
• HIV Vaccine Myths and Facts
• HVTN Trials

Also see the HIV Source collection of HIV links and resources.