Advancing Adolescent HIV Prevention and Care Through Implementation Science: An Agenda for Combating the Global AIDS Epidemic in Sub-Saharan Africa.

AIDS continues to be a major driver of adolescent mortality in Sub-Saharan Africa. Despite evidence of efficacy in this population, many efforts to address adolescent HIV have had limited impact across the region because of difficulty with implementation. The field of implementation science holds promise for addressing these challenges. The Fogarty-led Adolescent HIV Prevention and Treatment Implementation Science Alliance (AHISA) creates a platform for bidirectional learning between researchers and the users of research evidence that promotes the use of implementation science to strengthen adolescent HIV prevention and care across Africa. The unique contributions of AHISA are reflected in this supplement's articles which represent the collective learning of the Alliance; illustrate the value of implementation science in the context of adolescent HIV; and identify critical research gaps that should be addressed by implementation science in the future.

COVID-19 and global equity for health: The good, the bad, and the wicked.

Elvin Geng and co-authors discuss monitoring and achieving equity in provision of vaccines for COVID-19.

How will COVID-19 transform global health post-pandemic? Defining research and investment opportunities and priorities.

Michael Reid and co-authors introduce a Collection on the global health in the post-COVID-19 era.

Integrating Social Determinants in Decision-Making Processes for Health: Insights from Conceptual Frameworks-the 3-D Commission.

The inclusion of social determinants of health offers a more comprehensive lens to fully appreciate and effectively address health. However, decision-makers across sectors still struggle to appropriately recognise and act upon these determinants, as illustrated by the ongoing COVID-19 pandemic. Consequently, improving the health of populations remains challenging. This paper seeks to draw insights from the literature to better understand decision-making processes affecting health and the potential to integrate data on social determinants. We summarised commonly cited conceptual approaches across all stages of the policy process, from agenda-setting to evaluation. Nine conceptual approaches were identified, including two frameworks, two models and five theories. From across the selected literature, it became clear that the context, the actors and the type of the health issue are critical variables in decision-making for health, a process that by nature is a dynamic and adaptable one. The majority of these conceptual approaches implicitly suggest a possible role for data on social determinants of health in decision-making. We suggest two main avenues to make the link more explicit: the use of data in giving health problems the appropriate visibility and credibility they require and the use of social determinants of health as a broader framing to more effectively attract the attention of a diverse group of decision-makers with the power to allocate resources. Social determinants of health present opportunities for decision-making, which can target modifiable factors influencing health-i.e. interventions to improve or reduce risks to population health. Future work is needed to build on this review and propose an improved, people-centred and evidence-informed decision-making tool that strongly and explicitly integrates data on social determinants of health.

Improving Decision-Making for Population Health in Nonhealth Sectors in Urban Environments: the Example of the Transportation Sector in Three Megacities-the 3-D Commission.

Noncommunicable diseases (NCDs) represent a significant global public health burden. As more countries experience both epidemiologic transition and increasing urbanization, it is clear that we need approaches to mitigate the growing burden of NCDs. Large and growing urban environments play an important role in shaping risk factors that influence NCDs, pointing to the ineluctable need to engage sectors beyond the health sector in these settings if we are to improve health. By way of one example, the transportation sector plays a critical role in building and sustaining health outcomes in urban environments in general and in megacities in particular. We conducted a qualitative comparative case study design. We compared Bus Rapid Transit (BRT) policies in 3 megacities-Lagos (Africa), Bogotá (South America), and Beijing (Asia). We examined the extent to which data on the social determinants of health, equity considerations, and multisectoral approaches were incorporated into local politics and the decision-making processes surrounding BRT. We found that all three megacities paid inadequate attention to health in their agenda-setting, despite having considerable healthy transportation policies in principle. BRT system policies have the opportunity to improve lifestyle choices for NCDs through a focus on safe, affordable, and effective forms of transportation. There are opportunities to improve decision-making for health by involving more available data for health, building on existing infrastructures, building stronger political leadership and commitments, and establishing formal frameworks to improve multisectoral collaborations within megacities. Future research will benefit from addressing the political and bureaucratic processes of using health data when designing public transportation services, the political and social obstacles involved, and the cross-national lessons that can be learned from other megacities.

Masks Do More Than Protect Others During COVID-19: Reducing the Inoculum of SARS-CoV-2 to Protect the Wearer.

Although the benefit of population-level public facial masking to protect others during the COVID-19 pandemic has received a great deal of attention, we discuss for one of the first times the hypothesis that universal masking reduces the "inoculum" or dose of the virus for the mask-wearer, leading to more mild and asymptomatic infection manifestations. Masks, depending on type, filter out the majority of viral particles, but not all. We first discuss the near-century-old literature around the viral inoculum and severity of disease (conceptualized as the LD50 or lethal dose of the virus). We include examples of rising rates of asymptomatic infection with population-level masking, including in closed settings (e.g., cruise ships) with and without universal masking. Asymptomatic infections may be harmful for spread but could actually be beneficial if they lead to higher rates of exposure. Exposing society to SARS-CoV-2 without the unacceptable consequences of severe illness with public masking could lead to greater community-level immunity and slower spread as we await a vaccine. This theory of viral inoculum and mild or asymptomatic disease with SARS-CoV-2 in light of population-level masking has received little attention so this is one of the first perspectives to discuss the evidence supporting this theory.

Transforming Global Health by Improving the Science of Scale-Up.

In its report Global Health 2035, the Commission on Investing in Health proposed that health investments can reduce mortality in nearly all low- and middle-income countries to very low levels, thereby averting 10 million deaths per year from 2035 onward. Many of these gains could be achieved through scale-up of existing technologies and health services. A key instrument to close this gap is policy and implementation research (PIR) that aims to produce generalizable evidence on what works to implement successful interventions at scale. Rigorously designed PIR promotes global learning and local accountability. Much greater national and global investments in PIR capacity will be required to enable the scaling of effective approaches and to prevent the recycling of failed ideas. Sample questions for the PIR research agenda include how to close the gap in the delivery of essential services to the poor, which population interventions for non-communicable diseases are most applicable in different contexts, and how to engage non-state actors in equitable provision of health services in the context of universal health coverage.

Politics and Universal Health Coverage--The Post-2015 Global Health Agenda.

What political, social, and economic factors allow a movement toward universal health coverage to take hold in some low- and middle-income countries? Can we use that knowledge to help other such countries achieve health care for all?

PEPFAR Reauthorization by Congress Urgent for Global Health.

This Viewpoint discusses the importance of the US Congress reauthorizing funding for the President's Emergency Plan for AIDS Relief, a program developed in 2003 that has played a critical role in fighting HIV/AIDS worldwide as well as other emerging infections and noncommunicable diseases.

Assessing the impact of one million COVID-19 deaths in America: economic and life expectancy losses.

Between February 2020 and May 2022, one million Americans have died of COVID-19. To determine the contribution of those deaths to all-cause mortality in terms of life expectancy reductions and the resulting economic welfare losses, we calculated their combined impact on national income growth and the added value of lives lost. We estimated that US life expectancy at birth dropped by 3.08 years due to the million COVID-19 deaths. Economic welfare losses estimated in terms of national income growth supplemented by the value of lives lost, was in the order of US$3.57 trillion. US$2.20 trillion of these losses were in in the non-Hispanic White population (56.50%), US$698.24 billion (19.54%) in the Hispanic population, and US$579.93 billion (16.23%) in the non-Hispanic Black population. The scale of life expectancy and welfare losses underscores the pressing need to invest in health in the US to prevent further economic shocks from future pandemic threats.