How can we get close to zero? The potential contribution of biomedical prevention and the investment framework towards an effective response to HIV

Abstract

Background: In 2011 an Investment Framework was proposed that described how the scale-up of key HIV interventions could dramatically reduce new HIV infections and deaths in low and middle income countries by 2015. This framework included ambitious coverage goals for prevention and treatment services resulting in a reduction of new HIV infections by more than half. However, it also estimated a leveling in the number of new infections at about 1 million annually after 2015.

Methods: We modeled how the response to AIDS can be further expanded by scaling up antiretroviral treatment (ART) within the framework provided by the 2013 WHO treatment guidelines. We further explored the potential contributions of new prevention technologies: 'Test and Treat', pre-exposure prophylaxis and an HIV vaccine.

Findings: Immediate aggressive scale up of existing approaches including the 2013 WHO guidelines could reduce new infections by 80%. A 'Test and Treat' approach could further reduce new infections. This could be further enhanced by a future highly effective pre-exposure prophylaxis and an HIV vaccine, so that a combination of all four approaches could reduce new infections to as low as 80,000 per year by 2050 and annual AIDS deaths to 260,000.

Interpretation: In a set of ambitious scenarios, we find that immediate implementation of the 2013 WHO antiretroviral therapy guidelines could reduce new HIV infections by 80%. Further reductions may be achieved by moving to a 'Test and Treat' approach, and eventually by adding a highly effective pre-exposure prophylaxis and an HIV vaccine, if they become available.

Figure 1. Progression of HIV-infected adults from new infection to HIV-related death.

Figure 2. New HIV Infections in Low- and Middle-Income Countries by Scenario.

Key: Base = base projection with constant coverage of existing interventions and no new technologies. IF = achievement of Investment Framework 2015 targets scenario. IFE = IF plus adoption of WHO 2013 treatment guidelines. IFE + T&T = IF Enhanced plus impact of high Test and Treat scenario. IFE + High PrEP = IF Enhanced plus impact of high PrEP scenario. IFE+ High vac = IF Enhanced plus impact of HIV high vaccine scenario. Combined = combination of Investment Framework Enhanced and all three new technologies. Note: solid lines denote scenarios using existing technologies, dashed lines denote scenarios using technologies under development.

Figure 3. HIV-Related Deaths and Number Receiving ART in Low- and Middle-Income Countries by Scenario.

Key: Base = base projection with constant coverage of existing interventions and no new technologies. IFE = IF plus continued increases in ART coverage under WHO 2013 treatment guidelines. NPT = IFE + High T&T, PrEP, Vaccine = combination of IFE and high impact for all three technologies combined.

Figure 4. Cumulative Additional Resources Required by Scenario from 2011–2050 in Billions of US$ Discounted at 3% Compared to the Investment Framework 2015.

Key: IF Enhanced = IF plus adoption of WHO 2013 treatment guidelines. T&T = IF Enhanced plus high Test and Treat. PrEP = IF Enhanced plus high PrEP scenario. Vaccine = IF Enhanced plus high vaccine scenario. IFE+T&T+PrEP+Vaccine = IFE plus high scenarios for T&T plus PrEP plus HIV vaccine. Note: solid bars denote scenarios using existing technologies, striped bars denote scenarios using technologies under development.