Enteric Vaccines
Our portfolio focuses heavily on vaccines because we want to prevent children from suffering from enteric and diarrheal diseases. Our efforts include investments in vaccines for rotavirus and the leading bacterial causes of diarrheal and enteric disease: Shigella, cholera, and typhoid.
Rotavirus. Rotavirus is the most common cause of diarrheal hospitalizations and deaths in children under 5 in the developing world. Existing rotavirus vaccines have been shown to dramatically reduce the number of hospitalizations and deaths. WHO recommends their use in all countries, particularly in places where diarrhea is a major cause of death among children.
We work closely with Gavi and national governments to support the introduction and sustainable delivery of rotavirus vaccines where they are most needed and to ensure adequate supply and appropriate formulations, packaging, and labeling.
We also work with PATH and vaccine manufacturers in emerging economies such as India and Indonesia to invest in new rotavirus vaccines that will diversify the market, increase vaccine supply, and decrease costs.
Cholera. Cholera kills as many as 130,000 people each year and occurs in both epidemic and endemic settings. At least 51 countries in Sub-Saharan Africa and Asia have endemic cholera. Several recent outbreaks in Guinea, Haiti, Sierra Leone, Zimbabwe, and elsewhere have severely strained these countries’ under-resourced health systems.
With our support and the support of other international partners, WHO established a global oral cholera vaccine stockpile in 2013—a key milestone for cholera prevention and control. Millions of doses have been shipped to >20 countries for outbreak, humanitarian crises and endemic use.
Stable vaccine demand should expand supply, lead to more competitive pricing, and spur additional demand in 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 use of cholera vaccines in endemic areas.
Shigella. Shigella is a ubiquitous bacterial pathogen in most regions of the developing world, where it is a major cause of moderate to severe diarrhea in children under 5. Unlike rotavirus and cholera, there is no vaccine available against Shigella, but we believe it is possible and are investing in vaccine candidates and enabling tools to accelerate the development process.
Typhoid. Typhoid kills about 160,000 people each year, with the highest known burden in South Asia. The burden of typhoid in Africa is also substantial with several recent outbreaks. An effective and affordable vaccine is the best short-term solution for controlling typhoid fever in countries with poor access to clean water, sanitation, and hygiene, as well as high rates of antibiotic resistance.
We are working with the International Vaccine Institute and vaccine manufacturers to develop a conjugate vaccine that can be used in children under 2 and that will have a longer duration of protection than the current polysaccharide vaccine. In 2015, Bharat Biotech licensed Typbar TCV®, a new typhoid conjugate vaccine for India, and in January 2018 the vaccine was prequalified by WHO and several hundred thousand doses have now been used, including for outbreak control of a super-resistant typhoid strain in Pakistan. We are also exploring more broadly-protective vaccines that, for example, target both typhoid and paratyphoid. Important additional areas of work include understanding transmission dynamics and improving surveillance systems, including leveraging environmental surveillance, to accurately measure the disease burden.
Evidence Generation for Enteric Diseases
We work to generate evidence that can help enhance our understanding of burden, evaluate the impact of interventions, and plan future investment strategies. These efforts include studies to define the burden of diarrheal and enteric disease pathogens and assess the effects of vaccine introductions.
We are supporting several surveillance networks, including global pediatric diarrheal disease surveillance through WHO, typhoid surveillance in South Asia and Africa, and a larger network of foundation-funded sites through the Child Health and Mortality Prevention Surveillance (CHAMPS) network.