Changes in self-reported risky sexual behaviour indicators among adults receiving regular risk reduction counselling and optional initiation of pre-exposure prophylaxis in an HIV vaccine preparedness study in Masaka, Uganda

Background HIV risk reduction counselling may reduce risk-taking behaviours. Yet, concerns remain about risk compensation among individuals initiating pre-exposure prophylaxis (PrEP). Objective We assessed changes in risky sexual behaviour indicators among HIV vaccine preparedness study participants who received regular risk reduction counselling and referral for PrEP in Masaka, Uganda. Methods Adults (18-39 years) at high risk of HIV infection were enrolled in the study between July 2018 and December 2021. Data were collected on socio-demographic factors (baseline) and self-reported sexual risk behaviours (baseline, six monthly). HIV testing and risk-reduction counselling and referral for PrEP were done quarterly. Participants who had completed at least 1 year of follow-up were included in the analysis. Proportional differences and McNemar chi-square tests were used to assess changes in the prevalence of self-reported risky sexual behaviour indicators between baseline and 1 year. Logistic regression was used to assess the predictors of unchanged/increased HIV risk at 1 year. Results Three hundred participants [132 (44%) females, 152 (51%) aged & LE;24 years] were included in this analysis. Eighty-one (27%) participants initiated PrEP at 1 year. Compared to baseline, there were significant reductions in the prevalence of the following self-reported HIV risk indicators at 1 year (overall, among non-PrEP initiators, and among PrEP initiators): transactional sex, & GE;6 sexual partners, unprotected sex with & GE;3 partners, sex while drunk, and sexually transmitted infection diagnosis/treatment. Percentage differences ranged from 10% for individuals reporting at least six sexual partners to 30% for those reporting unprotected sex with three or fewer sexual partners. There was weak evidence of association between female gender and unchanged/increased HIV risk at 1 year (adjusted OR: 1.35, 95% CI (0.84-2.17)). No other indicators, including PrEP use, were associated with unchanged/increased HIV risk at 1 year. Conclusion Regular risk-reduction counselling may reduce risky sexual behaviour, while PrEP initiation may not lead to risk compensation.