Cost and impact of pre-exposure prophylaxis PrEP scale-up in South Africa and Zambia

This dissertation addresses the need for real-world evidence on the cost and effectiveness of HIV pre-exposure prophylaxis (PrEP) service delivery in resource-constrained settings, focusing on South Africa and Zambia. While oral PrEP is highly efficacious in trials, its real-world effectiveness is often limited by adherence challenges, and critical funding gaps threaten long-term program sustainability across Eastern and Southern Africa. To inform sustainable, evidence-based budgeting, this research pursued three main objectives: developing a novel, standardized metric to evaluate PrEP programs; determining the costs and cost-outcomes of diverse service delivery models; and assessing the cost-effectiveness of long-acting injectable PrEP (CAB-LA).
Analysis of service delivery models in Zambia revealed that implementation costs (US$394 to US$655 per client annually) are considerably higher than previous modelling estimates. Critically, programmatic costs - such as demand creation, training, and technical assistance - were identified as a sizeable cost driver. Complementary analysis in South Africa highlighted substantial variations in program effectiveness (0% to 42% clients on PrEP at six months), underscoring that tailored, context-specific delivery models, like community-based outreach, are important for reaching specific vulnerable populations. Furthermore, economic modelling demonstrated that CAB-LA is only cost-effective at an annual price below $16, significantly below current pharmaceutical projections.
These findings provide important empirical data for policymakers, challenging existing economic assumptions and informing resource allocation strategies that must balance epidemiological impact with economic efficiency. This work contributes towards the development of a foundation for sustainable, country-led implementation of HIV prevention technologies across sub-Saharan Africa.