Sexual risk behaviors, circumcision status, and preexisting immunity to adenovirus type 5 among men who have sex with men participating in a randomized HIV-1 vaccine efficacy trial: step study.

ABSTRACT:

Background

The Step Study found that men who had sex with men (MSM) who received an adenovirus type 5 (Ad5) vector-based vaccine and were uncircumcised or had prior Ad5 immunity, had a higher HIV incidence than MSM who received placebo. We investigated whether differences in HIV exposure, measured by reported sexual risk behaviors, may explain the increased risk.

Methods

Among 1764 MSM in the trial, 726 were uncircumcised, 994 had prior Ad5 immunity, and 563 were both uncircumcised and had prior Ad5 immunity. Analyses compared sexual risk behaviors and perceived treatment assignment among vaccine and placebo recipients, determined risk factors for HIV acquisition, and examined the role of insertive anal intercourse in HIV risk among uncircumcised men.

Results

Few sexu

SUBMITTER: Koblin BA 

PROVIDER: S-EPMC3392543 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature