What does preexposure prophylaxis mean for treatment; what does treatment mean for preexposure prophylaxis?

Both preexposure prophylaxis (PrEP) and treatment as prevention (TaP) have shown promise in contributing to HIV prevention, in models, observational cohorts and in real-world intervention studies. They share similarities, in that they use the same drugs, toxicity markers and may be focused on the same key populations. How to implement PrEP is still the source of much debate; effective coverage with TaP, with recent data on the positive impact of treatment at high CD4 counts, is still an ongoing challenge.

Treatment has demonstrated individual benefit even at CD4 counts above 350 cells/μl; PrEP has shown the effectiveness in real-world use.

This article discusses the intersection of the two interventions, some programmatic misconceptions and complexities, and argues that PrEP is a nuanced and useful adjunct to HIV programmes. PrEP can be rolled out in a way that complements treatment, possibly even within primary health clinics, and may be required for the many people in whom TaP currently fails. PrEP will need constant adaptation so as to maintain programmatic and cost-effectiveness, as the epidemiology of HIV changes with TaP rollout and expansion as CD4 restrictions are lifted. Finally, the article also argues that so-called ethical concerns around competing resources are relatively easily resolved.