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 ≤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, ≥6 sexual partners, unprotected sex with ≥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.