At a glance
- Enteric infections, which invade the intestinal tract, and diarrheal diseases, which are a common result of enteric infections, are the world’s third-largest killer of children under age 5, primarily in lower-income countries. Children who survive often face repeated infections, weaker immune response to oral vaccines, stunted growth, and impaired cognitive development.
- We invest in vaccines as a cost-effective way to protect children from four major pathogens—rotavirus, cholera, Salmonella Typhi (enteric fever), and Shigella—and we support research on gut damage to better address the consequences of enteric infections.
- Inadequate diagnostic tools are a major challenge in the health systems of many lower-income countries, often leading to missed diagnoses or incorrect treatment of health conditions. We support development of low-cost diagnostics for tuberculosis (TB), HIV, malaria, and women’s health conditions to improve the quality of care and enable smarter health spending.
- Traditional clinical disease surveillance is costly, rarely leads to early detection of disease outbreaks and timely response, and underestimates the burden of vaccine-preventable diseases. We focus on demonstrating how innovative and more cost-effective tools like genomic sequencing, wastewater and environmental surveillance, and data modeling can supplement clinical surveillance to improve public health decision-making in lower-income countries.
Our strategy
We work to advance the development and delivery of safe, affordable, and effective vaccines in lower-income countries for the leading causes of enteric and diarrheal diseases, which can be dangerous in young children if left untreated. We also support research on the global and regional burden of these diseases and the development of tools to model and assess disease transmission. This research helps inform decisions on when and how to deploy new interventions and expand the use of existing ones.
In addition, we support development of low-cost diagnostics in service of smarter health spending, particularly for TB, malaria, and women’s health conditions. We do this by fostering a healthy product pipeline and partnering with manufacturers to make low-cost products widely available.
Finally, we work to demonstrate how a series of innovative disease surveillance approaches can help improve public health decision-making in areas such as disease transmission and vaccine efficacy. Our toolkit of approaches includes genomic sequencing, wastewater and environmental surveillance, and data modeling, which are typically employed only in high-income countries but show immense promise for lower-income countries.
Areas of focus
We focus on advancing the development and delivery of vaccines to combat enteric infections and diarrheal diseases, which disproportionately affect children in lower-income settings.
We focus on advancing the development and delivery of vaccines to combat enteric infections and diarrheal diseases, which disproportionately affect children in lower-income settings.
Our efforts include investments in vaccines for rotavirus, the most common pathogen that causes moderate to severe diarrhea, and the leading bacterial causes of diarrheal diseases, cholera and Shigella. We also focus on typhoid, an enteric disease that affects populations with limited access to safe sanitation, clean water, and medical services.
Rotavirus. Rotavirus is the most common cause of diarrheal hospitalizations and deaths in children under age 5 in lower-income countries. Rotavirus vaccines have been introduced in more than 125 countries, saving thousands of lives every year. The World Health Organization (WHO) recommends their use in all countries, particularly in places where diarrhea is a major cause of child mortality. We work closely with Gavi, the Vaccine Alliance, and national governments to support the introduction and delivery of rotavirus vaccines to all infants globally. We also work with vaccine manufacturers in low- and middle-income countries, such as India and Indonesia, to invest in new oral rotavirus vaccines that will diversify the market, increase vaccine supply, and decrease costs.
Despite the success of current rotavirus vaccines, their effectiveness is often lower in low-resource settings than in higher-income countries. The reasons include a condition called gut enteropathy that is associated with multiple other enteric infections, inflammation, malnutrition, high maternal antibody levels, and issues within the microbiome. We are working with several partners to develop next-generation rotavirus vaccines that are more effective and can help increase vaccine uptake and impact in lower-income settings.
Cholera. Cholera is the archetypal disease of inequity, affecting the most vulnerable populations, particularly those with limited access to safe water and sanitation. Cholera kills as many as 140,000 people each year. At least 45 countries in sub-Saharan Africa and Asia have reported cholera in recent years. An increasing number of cholera outbreaks have occurred in the past decade, driven by humanitarian crises and climate change. Vaccines and safe water and sanitation remain the best defenses against cholera.
With support from our foundation and other international partners, WHO established a global oral cholera vaccine stockpile, managed by Gavi, in 2013—a key milestone for cholera prevention and control. The Global Task Force on Cholera Control has facilitated the shipment of more than 200 million doses of cholera vaccine to more than 31 countries for use during outbreaks and humanitarian crises and in endemic areas. The cholera vaccine supply remains insufficient, however, so we support additional cholera vaccine manufacturers in low- and middle-income countries. Stable vaccine supply should lead to more competitive pricing and spur additional demand from countries with a high burden of cholera.
We also support the development of evidence-based policy guidelines for oral cholera vaccine use in outbreak settings, as well as better data collection to build a case for the targeted use of cholera vaccines in endemic or “hot-spot” areas.
Typhoid. Typhoid fever and its cousin, paratyphoid fever, are significant public health problems in South Asia, Southeast Asia, and many parts of sub-Saharan Africa. Every year, typhoid infections kill over 100,000 people, primarily children in lower-income countries. Those living in poor, densely populated urban areas without clean water and sanitation infrastructure are affected at the highest rates.
Typhoid fever is becoming an even more dangerous public health problem due to rapid and unregulated urbanization in lower-income countries, combined with the emergence of multidrug-resistant typhoid.
Typhoid conjugate vaccines (TCVs) offer a solution. First developed in 2015 with our foundation’s support, these vaccines are a game-changer for preventing the spread of typhoid. They are the first typhoid vaccines to be approved for use in children under age 2—one of the groups most vulnerable to typhoid. They also provide long-lasting immunity and reduce the need for antibiotics, which helps prevent drug-resistant strains of typhoid from emerging and spreading. TCVs were developed and are now manufactured in South Asia and Southeast Asia, where the burden of typhoid is greatest.
More than 40 million children have already received a dose of TCV, and the results have been promising and remarkably consistent: Studies have shown that TCVs can prevent 80% or more of typhoid cases. The vaccine has been included in routine childhood immunization programs in countries including Pakistan, Liberia, Nepal, and Zimbabwe, and more countries are planning to introduce the vaccine soon. TCVs are helping us get closer to a world where no child dies from a vaccine-preventable disease.
Shigella. Shigella is a common bacterial pathogen in most lower-income regions, with an estimated 77,000 deaths in young children each year. Shigella infection is also associated with significantly reduced growth. Due to the infection’s growing resistance to multiple drugs, therapeutic options are limited, which makes developing a vaccine a priority.
No vaccine is currently available for Shigella, but we are working with public health partners, biotechnology companies, and in-country vaccine manufacturers to accelerate the development process, including by investing in early-stage candidates and analytical tools. We focus particularly on combination vaccine approaches.
Mitigating gut damage: Repeated enteric infections result in chronic inflammation and damage to intestinal structure and function that impacts nutrition and immune response. Malnutrition and an inability to respond to oral vaccines result in long term consequences on health and in lower impact of vaccination where it is most needed. We are exploring approaches to prevent or reverse gut damage to restore the ability of children to optimally absorb nutrients and improve vaccine response.
Diagnostics—devices and tests that identify whether someone has a particular health condition or disease—are essential for determining and guiding the right treatment, but they’re often unavailable where they’re needed most.
Diagnostics—devices and tests that identify whether someone has a particular health condition or disease—are essential for determining and guiding the right treatment, but they’re often unavailable where they’re needed most.
We invest in better, more affordable diagnostics because they are foundational to strong health systems. Our work spans innovation, manufacturing, and implementation, grounded in the belief that diagnostics are not just tools for detection but also catalysts for more effective and equitable health care.
Our current strategy focuses on end-to-end impact: identifying the highest-priority use cases across diseases such as TB, malaria, HIV, and sexually transmitted infections; building a pipeline of diagnostic platforms that can be developed and manufactured cost-effectively; and ensuring that these tools are used consistently and effectively at the point of care. In doing so, we seek out local partnerships, especially with manufacturers in India and China, to shape resilient regional ecosystems that can deliver high-quality diagnostics on a large scale. To ensure sustainable use, we ground our innovation efforts in real-world implementation settings. Through this work, we aim to demonstrate how timely access to low-cost diagnostics can improve health outcomes and make the most of health care spending.
Ultimately, we believe that better access to diagnostics leads to better decisions, more efficient programs, and stronger health systems.
Pathogen genomic sequencing is the process of decoding the genetic material of a disease-causing microorganism—such as a virus, bacterium, or parasite—to understand its structure, mutations, and evolution.
Pathogen genomic sequencing is the process of decoding the genetic material of a disease-causing microorganism—such as a virus, bacterium, or parasite—to understand its structure, mutations, and evolution.
It’s a powerful tool for disease surveillance because it can help identify specific strains, track transmission patterns, detect new variants, and inform public health responses such as vaccine updates and disease containment strategies.
As part of the response to COVID-19, we helped build significant genomic sequencing capacity in lower-income countries, where it was historically limited by cost and available equipment and expertise. We are now focusing on helping countries integrate pathogen genomics into routine public health surveillance for endemic health threats and diseases with outbreak potential, through partnerships with national public health leaders in Africa and Asia.
Wastewater and environmental surveillance is the practice of testing sewage for biological markers—such as viruses, bacteria, or antimicrobial resistance genes—that reflect the health of an entire community.
Wastewater and environmental surveillance is the practice of testing sewage for biological markers—such as viruses, bacteria, or antimicrobial resistance genes—that reflect the health of an entire community.
People often shed pathogens in their waste, often before showing symptoms, so this method, in theory, provides a cost-effective early-warning system for outbreaks without needing to test individuals. Adoption in lower-income countries has been slower than in higher-income countries due to gaps in sanitation infrastructure, lab capacity, and data systems. However, recent experience, especially during the COVID-19 pandemic, has sparked global interest in scaling up wastewater and environmental surveillance as a low-cost tool for real-time public health intelligence.
We are helping to show the value of this approach in lower-income countries through the development of better, lower-cost testing and analysis methods and demonstration projects.
Improved data modeling is essential for disease surveillance and public health decision-making because it helps fill gaps in real-world data, forecast future trends, and evaluate the potential impact of different interventions.
Improved data modeling is essential for disease surveillance and public health decision-making because it helps fill gaps in real-world data, forecast future trends, and evaluate the potential impact of different interventions.
In many settings, especially in lower-income countries, surveillance data can be incomplete or delayed. Models can synthesize available information to provide timely, evidence-based insights on where disease is spreading, who is most at risk, and which actions are likely to be most effective. This leads to smarter, more targeted, and more efficient public health responses.
Our modeling work includes support for the Institute for Health Metrics and Evaluation at the University of Washington, a public health research institute in Seattle. The institute produces the Global Burden of Disease study, which estimates the causes of death and disability worldwide, provides data-driven, impartial insights into disease trends over time, and examines financing for health. We also directly collaborate with modelers in lower-income countries to help build their modeling capabilities and support modeling of health data to inform local decision-making.
Why focus on enteric and diarrheal diseases?
Enteric and diarrheal diseases are the second-leading infectious cause of death among young children in lower-income countries, killing more than 340,000 children under age 5 each year. Children who survive often face repeated diarrheal infections in the early years of life, which can lead to serious, lifelong health problems. Evidence suggests an association between repeated infections and poor nutrient absorption, weaker immune response to oral vaccines, stunted growth, and impaired cognitive development. The ripple effects extend beyond health: Enteric and diarrheal diseases can hold kids back from school and limit their opportunities. By keeping them healthy, vaccines help children reach their potential so they can become productive members of their communities.
Research, funding, and political commitment to address these diseases are lacking in many places, which results in a dearth of critical information about the pathogens and the environmental factors that increase their occurrence. Effective and affordable tools for prevention and treatment exist, but most do not reach the poorest communities and regions.
The past 25 years have seen a significant decline in the number of children under age 5 dying from enteric and diarrheal diseases, in part due to socioeconomic development, improved water and sanitation systems, and better access to vaccines, diagnostics, and treatments. However, too many children still perish from infections that are entirely preventable or treatable. Prevention efforts that focus on vaccines in the short term and improvements in water, sanitation, and hygiene in the longer term can significantly reduce both suffering and death from these diseases.
Why focus on diagnostics?
Improving access to diagnostics in lower-income countries is essential for saving lives, strengthening health systems, and advancing global health equity. Some believe it’s cheaper to provide treatment without testing, but this often leads to wasted medicine, poor health outcomes, and bad data. Even though WHO has issued a list of recommended tests, very few countries have fully followed it. Without affordable and easy-to-use diagnostics, it’s hard to deliver quality care and even harder to build strong, efficient health systems.
Why focus on genomics, epidemiology, and data modeling?
Improved disease surveillance in lower-income countries is essential for early detection of outbreaks, informed public health responses, and global health security—especially in regions where the burden of infectious disease is highest and surveillance systems are often weakest. We focus on genomics, epidemiology, and data modeling because they are high-value, cost-effective approaches that have the potential to supplement—and improve—traditional clinical disease surveillance programs.
