John Stover

China’s commitment to implementing established and emerging HIV/AIDS prevention and control strategies has led to substantial gains in terms of access to antiretroviral treatment and prevention services, but the evolving and multifaceted HIV/AIDS epidemic in China highlights the challenges of maintaining that response. This study presents modeling results exploring the potential impact of HIV vaccines in the Chinese context at varying efficacy and coverage rates, while further exploring the potential implications of vaccination programs aimed at reaching populations at highest risk of HIV infection. A preventive HIV vaccine would add a powerful tool to China’s response, even if not 100% efficacious or available to the full population.

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. 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. 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. 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.

The Spectrum program is used to estimate key HIV indicators for national programmes. The purpose of the study is to describe the key updates made to Spectrum in the last 2 years to produce the version used in the 2013 global estimates of HIV/AIDS. The United Nations Programme on HIV/AIDS (UNAIDS) Reference Group on Estimates, Models and Projections regularly reviews new data and information needs and recommends updates to the methodology and assumptions used in Spectrum. The latest data from surveys, census and special studies are used to estimate key parameter values for countries and regions. Country-specific life tables prepared by the United National Population Division (UNPD) have been incorporated into Spectrum's demographic projections replacing the model life tables used previously. This update includes revised estimates of non-AIDS life expectancy. Incidence among all adults 15-49 years generated from curve fitting to surveillance and survey data is now split by age using incidence rate ratios derived from Analysing Longitudinal Population-based HIV/AIDS data on Africa Network data for generalized epidemics. Methods for estimating the number of AIDS orphans have been updated to include the changing effects of PMTCT and antiretroviral therapy programmes. Procedures for estimating the number of adults eligible for treatment have been updated to reflect the 2013 WHO guidelines. Program data on AIDS mortality has been used to estimate prevalence trends in Argentina, Brazil and Mexico for the 2013 estimates. Spectrum was updated for the 2013 round of HIV estimates in order to support national programmes with improved methods and data to estimating national indicators.

This analysis examines the impact of the UNAIDS Investment Framework for HIV on adolescents to determine: a) impact of investing in prevention for adolescents 10-19 on new HIV infections, the number of adolescents living with HIV, and adolescent AIDS deaths; and b) cost of programs by type. We modeled four scenarios: (1) the Base scenario assumes constant coverage for prevention and treatment, (2) the Investment Framework scenario assumes scale-up of services to reach universal coverage targets by 2015, (3) the Investment Framework Delayed scenario assumes that coverage targets are not achieved until 2020, and (4) the Pessimistic scenario illustrates the disadvantages of poor implementation. Scaling up investments and services according to the Investment Framework could avert 2 million new adolescent HIV infections by 2020. A five-year delay would reduce impact by one-third. Poor implementation would result in little decline in the annual number of new infections. Achieving the Investment Framework will require a 45% expansion in annual expenditure to nearly $5.5 billion by 2014. After 2014 resource needs will decline somewhat due to reductions in new infections. One-third of these resources are for Basic Programs, one-fourth for Critical Enablers, and 40 percent for Development Synergies.

Objectives: The present study presents estimates of the number of people who would become newly eligible for antiretroviral therapy if all countries adopted the 2013 WHO treatment guidelines. It also shows the cost and impact that would result if coverage expanded to 80% of those eligible. Methods: The AIDS Impact Model (AIM) and the Goals model within the Spectrum modelling system were used for these estimates. Projections of costs and AIDS deaths are based on estimates for 116 low-income and middle-income countries. Projections of impact on HIV incidence are based on simulation modelling for 24 high burden countries, with the results scaled up to represent all low-income and middle-income countries. Results: If the 2013 guidelines were adopted universally, the number eligible for treatment would rise to 28.6 million in 2013. Achieving 80% coverage would mean 28 million on antiretroviral therapy by 2025, and would avert 2.9 million deaths and 3.9 million new infections from 2013 to 2025 compared with the 2010 guidelines. Conclusion: The 2013 guidelines significantly expand the number eligible for treatment. Reaching those newly eligible will require additional resources, but is likely to produce significant benefits.

This study modelled estimates of the cost and impact of male circumcision (MC) under different scenarios using the Decision Maker's Program Planning Tool on data from Uganda. Results showed that the number of new adult HIV infections could be reduced by 23 000 if MC could be increased from the current 25% to 80% by 2015. The incidence of HIV could be reduced by 0.2 percentage points over the same period. If a scale up programme is to meet a target of 80% by 2015 then the annual number of MCs performed should be over twice as many as those performed in 2011. The discounted net cost per infection averted would be US$559 for the period 2011-2015 and the country would save US$6 841 per infection. A scale up of MC will reduce HIV prevalence and incidence substantially and it would be highly cost effective. The government should mobilise funding to meet high MC targets that would deliver the desired reduction in prevalence and incidence in a short period of time.

A number of data sets show that high parity births are associated with higher child mortality than low parity births. The reasons for this relationship are not clear. In this paper we investigate whether high parity is associated with lower coverage of key health interventions that might lead to increased mortality.