Effectiveness of UNAIDS targets and HIV vaccination across 127 countries

Abstract

The HIV pandemic continues to impose enormous morbidity, mortality, and economic burdens across the globe. Simultaneously, innovations in antiretroviral therapy, diagnostic approaches, and vaccine development are providing novel tools for treatment-as-prevention and prophylaxis. We developed a mathematical model to evaluate the added benefit of an HIV vaccine in the context of goals to increase rates of diagnosis, treatment, and viral suppression in 127 countries. Under status quo interventions, we predict a median of 49 million [first and third quartiles 44M, 58M] incident cases globally from 2015 to 2035. Achieving the Joint United Nations Program on HIV/AIDS 95-95-95 target was estimated to avert 25 million [20M, 33M] of these new infections, and an additional 6.3 million [4.8M, 8.7M] reduction was projected with the 2020 introduction of a 50%-efficacy vaccine gradually scaled up to 70% coverage. This added benefit of prevention through vaccination motivates imminent and ongoing clinical trials of viable candidates to realize the goal of HIV control.

Keywords: HIV; effectiveness; mathematical model; vaccination.

Fig. 1.

Infections averted between 2015 and 2035, compared with maintaining status quo diagnosis, treatment, and viral suppression, by the UNAIDS 95–95–95 target (Top); rollout of vaccination in 2020 while maintaining status quo levels of diagnosis, treatment, and viral suppression (Middle); and the UNAIDS 95–95–95 target combined with 2020 vaccination rollout (Bottom). Predictions are medians over 1,000 model simulations in which parameter values were sampled from data-driven distributions. See SI Appendix, Figs. S4–S140 for projections and uncertainty estimation globally, by region, and by country.

Fig. 2.

Effectiveness of HIV interventions globally (Left) and for selected countries (remaining columns) in terms of cumulative incidence (top row), annual incidence per million population (second row), PLHIV (third row), and cumulative HIV mortality (bottom row). Predictions are medians over 1,000 model simulations in which parameter values were sampled from data-driven distributions. See SI Appendix, Figs. S4–S140 for median and uncertainty estimates of effectiveness of HIV interventions for all 127 countries.

Fig. 3.

Effectiveness of HIV interventions for UNAIDS regions in terms of cumulative incidence from 2015 to 2035 (Upper) and number of PLHIV in 2035 (Lower). Medians (colored bars) and first and third quartiles (black error bars) were generated from 1,000 model simulations in which parameter values were sampled from data-driven distributions. See SI Appendix, Figs. S4–S140 for median and uncertainty estimates of the effectiveness of HIV interventions for UNAIDS regions.

Fig. 4.

Scenario analysis for vaccination under six strategies, globally (Left) and for selected countries (remaining columns), with variation in vaccine efficacy, ultimate coverage, initiation date of vaccination rollout, and rate of scale-up. Vaccine scenario projections are generated from simulations parametrized with modal values.