From 1992 to 2007, the ANRS (France Recherche Nord & Sud Sida-HIV Hépatites) set up a network of healthy volunteers at low risk of HIV infection and participating in preventive HIV vaccine phase I and II trials. The objectives of the ANRS COHVAC volunteer cohort include the social consequences of trial participation and their sexual behavior over time. For 488 volunteers who received a vaccine candidate, 462 selection files were collected, and from 2008 to 2016, 355 volunteers participated in the prospective cohort, including self-administered and face-to-face questionnaires administered annually. The volunteer population is relatively old, with social characteristics and engagement in society rather high. Most volunteers and people around them well accepted the trials, and participation in vaccine trials was not followed by increased risk-taking regarding HIV infection years later.