Welcome!

The primary study results for Explore are now available! Please go to the Primary Study Results section of this site to learn the results.

The HIVNET 015 study, colloquially referred to as "Explore," is the first study to test a behavioral intervention specifically for men who have sex with men (MSM) over an extended period of time using HIV infection as the primary endpoint.

Many research studies have been conducted involving populations of MSM to identify interventions which can help MSM to reduce the frequency of sexual behaviors that put them at risk of getting HIV. Extensive changes in risk behaviors have occurred among MSM but, in recent years, HIV infections, other sexually transmitted diseases and sexual risk behaviors have been increasing, emphasizing the critical need for identifying effective prevention interventions. Explore examined the potential of one such intervention to reduce HIV infection rates among MSM.

From January 1999 to February 2001, 4,295 HIV-negative MSM were enrolled in six US cities: Boston, Chicago, Denver, New York, San Francisco and Seattle. Men were eligible if they were age 16 or older and reported having engaged in anal sex with one or more men during the past year. Study participants completed extensive questionnaires regarding sexual behaviors, alcohol and drug use, and occurrence of sexually transmitted diseases.

Following enrollment, study participants in the standard treatment arm underwent HIV testing, received HIV-prevention counseling and completed extensive questionnaires regarding sexual behaviors, alcohol and drug use, and occurrence of sexually transmitted diseases every six months. Study participants in the intervention treatment arm completed the same activities as those in the standard arm, but they received additional counseling in the form of multiple intensive behavioral counseling sessions (with motivational interviewing and cognitive behavior theory, for example, as key components) during the first three to four months of their study involvement period. Afterward, participants received "booster" sessions every three months (for up to, on average, 3.25 years).

The Explore study closed on 31 July 2003. Since that time, the Explore primary results paper has been published in The Lancet. (You can find that paper here.) For more information on the paper, and on the results in general, go to the Primary Study Results page.

Explore Study Information

Some important documents associated with Explore are being made publicly available through this website; please refer to the "Document Center" on the right side of this page for links to those documents. Included among the documents are the study protocol and counseling intervention manual. Please feel free to view and download these documents for your reference.  Listed below are the study co-chairs and principal investigators (with links to their respective email addresses). If you need more information on the Explore study, please contact one of the co-chairs or PIs.

Explore Study Sites

• Boston: Fenway Community Health Center & Latin American Health Institute
• Chicago: Howard Brown Health Center
• Denver: Denver Department of Public Health
• New York: Project Achieve
• San Francisco: San Francisco Department of Public Health
• Seattle: University of Washington

Explore Ancillary Studies

In addition to the conducting the main study, Explore provided an opportunity for the completion of several ancillary studies, or studies that operated within Explore and depended on the Explore cohort for study participants. News regarding ancillary study research papers will appear on the Research page as it becomes available. For more information on the ancillary studies, please contact the individuals listed next to each study, below. The ancillary studies are: 

• A Study of Anal HPV Infection and Neoplasia as Risk Factors for HIV Seroconversion Among Participants in HIVNET 015; Joel Palefsky, M.D.  and Peter Chin-Hong, M.D.
• A Study of Human Herpesvirus 8 Among Participants in HIVNET Protocol #015; Corey Casper, M.D.
• Prevalence and Risk Factors For Acquisition of Pharyngeal Gonorrhea In Cohorts of Men Who Have Sex With Men; Grant Colfax, M.D.
• A Qualitative Analysis of Explore Counseling Sessions; Patrick Barresi, M.P.H.
• The Impact of Traumatic Current Events on the HIV Risk Taking Behaviors and Attitudes of Men Who Have Sex with Men: An Inquiry into the Effects of September 11th, 2001 on Boston's Cohort of Explore; Liz Salomon, Ed.M
• The Prevalence of Within Group Sexual Behavior and the Impact of Group Normative Identity on the HIV Risk Taking Behavior of Men Who Have Sex with Men; Matthew Mimiaga

Explore Eligibility Criteria

Volunteers were eligible for participation within Explore if they met each of the following conditions:

• Male, age 16 years and older.
• Able and willing to provide written informed consent.
• HIV-seronegative by licensed enzyme-linked immunoabsorbent assay (ELISA) or HIV-seronegative by Western blot (WB) if found to be HIVseropositive by licensed ELISA.
• Reports anal intercourse (receptive or insertive, protected or unprotected) with another man in the 12 months prior to enrollment.
• Available for the duration of the study.
• Willing and able to participate in all scheduled study visits and tests (unwillingness to donate rectal swab specimen is not exclusionary).
• Willing and able to provide adequate information for locator purposes.

Volunteers were NOT eligible to participate in Explore if any of the following conditions applied to them:

• Have been in a mutually monogamous relationship for two years or more with a known HIV antibody negative male. "Monogamous" is defined as a relationship in which the members of the couple engage in sexual activities only with each other, excluding all others.
• Have an obvious psychological/psychiatric disorder that would invalidate the informed consent process, or otherwise contraindicate participation in the study.
• Have any other condition which in the opinion of the study site Principal Investigator will interfere with achieving the study objectives. In such cases the site Principal Investigator will discuss the condition with the Protocol Co-chairs and Domestic Master Contractor (DMC) Protocol Specialist prior to participant notification.
• Were enrolled in the HIVNET 015 Pilot Study.
• Are enrolled in HIVNET Protocol 014.
• Are enrolled in any HIV vaccine trial (Phase I, Phase II, Phase IIB and Phase III trials), including the AIDSVAX Phase III trial sponsored by VaxGen, Inc.

A total of 4,295 participants were enrolled in the Explore study. For the number of participants enrolled at each study site, please see the "Study Summary" table below.

If you would like information regarding the study which is not available on the website, please contact one of the study co-chairs or principal investigators, above. Clicking on a name will open an email to that person in a new window.

The Explore study received support from the HIV Prevention Trials Network and was sponsored by the National Institute of Allergy and Infectious Diseases. Additional funding was provided by the National Institute of Child Health and Human Development, and the National Institute on Alcohol Abuse and Alcoholism, the National Institute on Drug Abuse, the National Institute of Mental Health, and the Office of AIDS Research, of the National Institutes of Health, US Dept of Health and Human Services. The study was conducted through contracts with Abt Associates Inc., Family Health International, the HVTN Central Lab, and the Fred Hutchinson Cancer Research Center, and subcontracts with the Denver Dept of Health and Hospitals, the Fenway Community Health Center, the Howard Brown Health Center, the New York Blood Center (Columbia University), the San Francisco Department of Public Health (Public Health Foundation Inc.), and the University of Washington.

NIAID is a component of the National Institutes of Health (NIH). NIAID supports basic and applied research to prevent, diagnose, and treat infectious and immune-mediated illnesses, including HIV/AIDS and other sexually transmitted diseases, illness from potential agents of bioterrorism, tuberculosis, malaria, autoimmune disorders, asthma and allergies.