A recorded number of 217,000-608,000 people die annually because of infection of NTDs. This low mortality rate generally influences global investment in vaccine development; therefore, reduced interest could be explained by the low percentage of people who die from NTDs. However, mortality rate does not signify the effects of worker capacity and productivity that result from population outbreaks of NTDs. Neglected tropical diseases are estimated to result in 112 million disability-adjusted life-years lost annually. This number exceeds the global disease burden and disability from HIV/AIDS, supporting the argument that NTDs should be a major public health concern. 

High Morbidity-Low Mortality Conditions

Emerging diseases, such as SARS, have predominantly affected wealthier nations making these diseases a national concern in developed countries. NTDs are ancient diseases that impact rural populations that do not share the same access to governmental aid or public health services. The geographic location of the diseases, such as the Gulf of Mexico, allows national governments to underestimate the severity of NTDs. 

Hidden in Remote Areas

NTDs occur in rural populations primarily located in the poorest communities of Africa, Latin America and Asia. Consequently, there is a limited commercial market for NTD vaccines; thus, upscaling investment for these vaccines is unlikely due to the current profit driven motivation of pharmaceutical companies. Without the appropriate assurance that companies will recover their financial investments in research and development, multinational corporations have been reluctant to support vaccine development initiatives for NTDs. Additionally, developing vaccines for soil-transmitted helminths and protozoan diseases require complex research and an intricate understanding of the pathogenesis of each of these disease causing microorganisms. 

Expensive Research & Development

There are three reasons that explain the reduced global involvement in vaccine development for neglected diseases. These include:

- High morbidity-low mortality conditions
- Hidden in remote areas
- Expensive research and development



Tulane University

Neglected tropical diseases disproportionately affect the world’s poorest populations or the “bottom billion”, a total 1.4 billion people living below the poverty level. These populations suffer from bacterial, protozoal, viral and helminthic infections which include chagas disease, hookworm, dengue fever and schistosomiasis. These diseases contribute to poverty as they adversely affect child cognitive development and worker productivity, thus promoting a generational cycle of poverty. Vaccines that target these childhood and neglected diseases are referred to as “Anti-Poverty Vaccines”. Although vaccine development that target childhood diseases have overcome efforts to combat NTDs, development and delivery of NTD vaccines have currently become financially incentivized. However, further stimulation of large pharmaceutical companies and vaccine distributors is needed to promote vaccine development for NTDs. 

Anti-Poverty Vaccines

Hotez, P. (2011). A handful of ‘antipoverty’ vaccines exist for neglected diseases, but the world’s poorest billion people need more. Health Affairs, 30(6), 1080-1087. doi:10.1377/hlthaff.2011.0317

A Handful Of ‘Antipoverty’ Vaccines Exist For Neglected Diseases, But The World’s Poorest Billion People Need More

The implementation of vaccine development for childhood diseases and neglected tropical diseases, promoted by the Bill & Melinda Gates Foundation, began in 2010 and has been named the “Decade of Vaccines”. This vaccine campaign attempts to aid populations living in the poorest conditions compared to developed nations across the globe. Significant progress has been made to increase accessibility of vaccines that combat childhood killer diseases such as rotavirus and measles. The success of this program is attributed to multinational cooperation and collaboration between pharmaceutical companies. The Program for Appropriate Technology in Health (PATH) has already made significant contributions to vaccine development and administration. Additionally, financial incentives placed by governmental authorities have created a market commitment by big pharmaceutical companies. 

Decade of Vaccines

Although efforts to combat childhood killer diseases have been immense, consequently, there have been reduced actions to curb the global disease burden of NTDs. Although neglected diseases are caused by numerous types of disease causing pathogens, these diseases have geographic and functional similarities. In areas of extreme poverty, it is not unusual to discover multiple neglected diseases operating at the same time and within the same population. Due to these commonalities, the same global health policy framework has been implemented to understand the conditions that promote NTD transmission. It is essential that the same global attention for childhood killer diseases is directed towards NTD control and treatment to ensure that the world’s most marginalized communities are not our last priority. 


Childhood Diseases vs. Neglected Tropical Diseases

Absence of Investment in Vaccine Development

Vaccines that target neglected tropical disease are categorized into three different groups
- Category 1: No Vaccine Required
- Category 2: Veterinary and Transmission Blocking Vaccines
- Category 3: Human Anti-Poverty Vaccines



Anti-Poverty Vaccines for NTDs

Several vaccines for neglected tropical diseases are in clinical phases of development or early research. The collaboration between university laboratories, product development partnerships and public-sector manufacturers has promoted vaccine construction and manufacturing. Human vaccines for hookworm infections are currently entering Phase II clinical trials. Vaccines for Chagas disease, food-borne trematode infections and onchocerciasis are in a preclinical phase of development. 

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