Uganda has the most realistic anti-HIV program there is.
“Zero Grazing”
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1544373/
There has been considerable interest in understanding what may have led to Uganda’s dramatic decline in HIV prevalence, one of the world’s earliest and most compelling AIDS prevention successes. Survey and other data suggest that a decline in multi-partner sexual behavior is the behavioral change most likely associated with HIV decline. It appears that behavior change programs, particularly involving extensive promotion of zero grazing (faithfulness and partner reduction), largely developed by the Ugandan government and local NGOs including faith-based, womens, people-living-with-AIDS and other community-based groups, contributed to the early declines in casual/multiple sexual partnerships and HIV incidence and, along with other factors including condom use, to the subsequent sharp decline in HIV prevalence. Yet the debate over what happened in Uganda continues, often involving divisive abstinence-versus-condoms rhetoric, which appears more related to the culture wars in the USA than to African social reality.
This article is from 2007. A post on the same site, dated 2013, mentioned “The need to reemphasize behavior change.”