Antibodies prevent infection. Most vaccines cause the body to make antibodies. If you get an HIV vaccine, your body may make antibodies to HIV. Standard HIV tests search for HIV antibodies as a sign of infection. Because of this, your HIV test results could come back positive even if you are not infected with HIV. This is called a VISP (Vaccine-Induced Seropositive) test result. You may also see this called Vaccine-Induced Seroreactive (VISR).
Frequently Asked Questions about VISP
Where can I get the right test for HIV?
You can get the right HIV test at the study site for free. After you leave the study you can continue to go to your study site to request HIV testing. If you are no longer located near your study site, the HVTN VISP Testing Service can help you get HIV testing in your area. The testing is free.
Getting the right test will prevent an incorrect diagnosis of HIV. Your study site or the VISP Testing Service can provide the right test.
Why don’t standard HIV tests look for actual HIV?
Standard HIV tests that look for antibodies are quick, reliable and affordable. Tests that look for the virus are expensive and not commonly used for an initial diagnosis.
What is “opt-out” testing for HIV?
“Opt-out” testing for HIV means that HIV tests may be done routinely unless a patient refuses to have the testing done. For more information on the Center for Disease Control’s (CDC) recommendations for HIV testing in the U.S., please visit:
For (U.S.) state-specific information, please visit:
For other information about HIV testing guidelines in your country, please visit:
What does “opt-out” testing mean for me?
You should tell your healthcare provider about your HIV vaccine study participation and refuse HIV testing. Even if your healthcare provider does not mention the HIV test, be sure to tell them that you do not want an HIV test because you are (or were) an HIV vaccine study participant.
How can I explain this situation to my healthcare provider?
No one can force you to have an HIV test for any reason.
- If anyone asks to test you for HIV or to draw your blood, tell them you are in (or have been in) an HIV vaccine study and that you need to get all your HIV tests at the study site.
- Explain that being tested outside of your study site or the HVTN VISP Testing Service could result in an incorrect diagnosis of HIV infection.
- Give the provider your study coordinator’s contact information. Ask the provider to call the study site or the HVTN VISP Testing Service directly (U.S. toll free: 1-800-327-2932).
- If you have to, simply say “no” to the HIV test, and then ask the study site or the HIV Vaccine Trials Network to help. We are happy to work with you to resolve your situation.
How long does VISP last?
If you have tested VISP, the antibodies may fade quickly or they may last for several years. In some cases, participants continue to test VISP for more than 20 years.
Can VISP be passed from one person to another?
- In most cases, no. If you have tested VISP you cannot pass the antibodies to another person by kissing or through sexual contact.
- If you are pregnant, we think there may be a chance that you could pass the vaccine antibodies to your baby. Although this has not been shown to happen with HIV study vaccines, we know that this happens with other vaccines, like the tetanus vaccine. Vaccine antibodies that mothers pass to their babies are temporary and go away over time, and they are not harmful to the baby. The HVTN can arrange for you and your baby to have accurate HIV testing for free for as long as it is needed.
- In order to donate blood or organs, the donation site will screen you using an HIV antibody test. If you test positive for HIV antibodies you may be unable to donate an organ. You may also be permanently banned from blood donation even though you are not infected with HIV.
How will a VISP test result affect me?
- If someone believes you are infected with HIV, you could face discrimination and/or other problems. For example, you could have problems with medical or dental care, employment, insurance, a visa for traveling, or entry into the military. You might not be allowed to donate blood or other organs. If you are pregnant, you may have to explain your situation to avoid receiving any HIV treatment during your pregnancy or labor/delivery.
- If you are planning to apply for insurance, employment, or the military, please inform your study site right away. The insurance company, employer, or military agency may not accept HIV test results from the HVTN. However, the HVTN can work with them to ensure the right test is done that will show your true HIV status.
What happens if I move far away from the study site where I participated in an HIV vaccine study?
For U.S. participants, call the HVTN VISP Testing Service at 1-800-327-2932 during business hours, Pacific Time. For participants outside the U.S., call your study site and they can assist you with testing for HIV. If you are unable to reach someone at your study site, send an email to email@example.com to request testing.
The HVTN VISP Testing Service provides HIV testing for participants who have received a study HIV vaccine in a National Institutes of Allergy and Infectious Diseases (NIAID) Division of AIDS (DAIDS)-funded HIV preventive vaccine trial and who are no longer able to be tested at their study site.
Will my information be confidential?
Yes. All of your information will be stored in a limited-access, password-protected, secure computer database. Access to your information will be limited to the HVTN VISP counselors. No identifying information concerning the testing will be released to any third party without your written approval, except when required by law.
How long does the HVTN VISP Testing Service take to provide test results?
Approximately 2 weeks.
Am I eligible for the HVTN VISP Testing Service?
- If you participated in an HIV Vaccine Trials Network (HVTN), AIDS Vaccine Evaluation Group (AVEG), or HIV Network for Prevention Trials (HIVNET) HIV preventive vaccine study, AND
- If you received an HIV vaccine*, AND
- You are willing to provide consent to have your blood drawn and for HIV testing.
- If you have a confirmed HIV infection, OR
- If you are currently enrolled in an HIV Vaccine Trial,** OR
- As a former study participant, you received a placebo.
* If you are not sure if you received an HIV vaccine, call the HVTN VISP Testing Service (1-800-327-2932).
**If you are currently enrolled in an HIV vaccine trial, your testing is provided by your trial site. If for some reason you are unable to be tested at your site, you can contact your study site or the HVTN VISP Testing Service (US toll free: 1-800-327-2932).
What if I live outside the U.S.? Will I have access to the HVTN VISP Testing Service?
The HVTN VISP Testing Service is open in the United States. Expansion of the testing service in southern Africa is underway. For locations outside of the U.S., please contact your study site or email firstname.lastname@example.org to request testing.
For more information about getting the right test for HIV
Contact your study coordinator at the HIV vaccine study site or the HVTN VISP Testing Service at (US toll free) 1-800-327-2932.