HIV Vaccines Questions and Answers For HIV Prevention Workers

Date: January 1, 2003
Source: National Institutes of Health (NIH)
Author: National Institute of Allergy and Infectious Diseases (NIAID)

1. Why do I need to know about HIV vaccine research?

As a prevention worker, you are in contact with different segments of the community and many people will turn to you for all types of information about HIV. Therefore, it is important for you to be able to answer questions concerning HIV vaccines, microbicides and other areas of HIV prevention research, in addition to providing information about HIV testing and risk reduction. Also, some of the people you are in contact with may be enrolled in an HIV vaccine trial and it is important for you to know how it can affect them and their seropositive status.

2. How does HIV vaccine research affect HIV prevention activities?

An HIV vaccine that is simple to administer, inexpensive, and effective, would be the most optimal prevention strategy. However, even when an HIV vaccine becomes widely available, a combination of preventive approaches will likely be required to protect individuals and the public against HIV infection, and control the global AIDS epidemic. Such approaches include:

  • Prevention strategies directed at individuals or communities for reducing risk of HIV transmission associated with sexual activity and/or with injection drug use
  • Microbicides for vaginal or rectal use
  • Antiretroviral therapy to care for those already infected and to reduce the infectiousness of HIV-infected persons
  • Treatment of sexually transmitted diseases (STDs) that are cofactors for HIV transmission
  • Prophylaxis to prevent mother-to-child transmission
  • A safe and effective HIV vaccine

In this context, HIV vaccines can be viewed as an integral component of a comprehensive HIV prevention strategy.

3. What are the basic facts about HIV vaccines?

There are several important things you need to know about HIV vaccines.

  • HIV vaccines being tested in humans do not contain HIV and cannot cause HIV. However, because HIV vaccines stimulate the body's production of antibodies to prevent infection, a trial participant may test positive on a standard HIV test (i.e., ELISA) depending on the vaccine and their response to the vaccine. Other tests are available to determine if the volunteer is actually infected with HIV as a result of their own behavior-related exposure to HIV.
  • If HIV vaccine trial participants engage in behaviors that expose them to HIV, they may become infected with HIV. In your capacity as a prevention worker, it is important for you to continue to stress the importance of safe behaviors that will reduce the risk of HIV infection, just as you would with others in the community.
  • At present, there is not an HIV vaccine. Contrary to what some people in the community may think, an HIV vaccine is not currently available. Research is underway to find a safe and effective vaccine that will protect people from being infected with HIV, but it will continue to take more time until a promising vaccine is discovered.

4. How will I know if someone is an HIV vaccine trial participant?

Prior to testing, it would be a good idea for you to ask if the individual is participating or has participated in an HIV vaccine trial. If the answer is yes, you should refer them back to their research site for HIV counseling and testing. Staff at the site will be able to provide testing that can differentiate between a volunteer actually being infected as a result of his or her own behavior and a positive result induced by the vaccine. If the volunteer knows they received placebo, or otherwise does not have circulating antibodies from the vaccine and their follow-up in the trial has been terminated, testing can proceed as usual.

5. Should I refuse to provide HIV testing to an HIV vaccine trial participant?

No. You should never refuse to provide HIV testing. However, you should very strongly encourage that the person be tested at his/her research site and explain that testing could reveal whether or not they are receiving the vaccine or a placebo, which may affect the outcome of an ongoing trial.

6. What if an HIV vaccine trial volunteer still wants to be tested at my clinic/health center?

If an HIV vaccine trial volunteer wants to be tested at your site rather than return to his/her research site for testing, you should make note that this individual is participating in an HIV vaccine study on the laboratory form. You should also request that, if the ELISA and Western Blot tests are positive, that a PCR (Polymerase Chain Reaction) test be conducted in order to determine whether the volunteer is actually infected with HIV as a result of his or her own behavior-related exposure to HIV.

7. Where can I go for more information?

For more detailed information about HIV vaccine and current research, you can visit the National Institute of Allergy and Infectious Diseases (NIAID) website at or the HIV Vaccine Trials Network at

For general information about HIV vaccines as well as a comprehensive database that can be searched for HIV vaccine trials by location or product, you can visit the AIDSinfo website at