Neglected tropical diseases (NTDs) are the most common affliction of the world’s poorest people. Thriving in communities that lack access to health services, adequate sanitation and clean water, NTDs blind, disable and disfigure, trapping families in a cycle of poverty and disease. Nearly one in six people globally has at least one of these 17 diseases.
Many of the most common NTDs can be treated and prevented for less than 50 cents per person per year. Pharmaceutical companies, governments and global health organizations – united in part by the London Declaration on NTDs, signed five years ago this week – have worked together to increase access to medicine. In 2015 alone, pharmaceutical companies donated 2.5 billion tablets and have pledged millions more to help control and eliminate NTDs by 2020. By the end of 2015, an estimated 62 percent of people in need of treatment received medicine.
The approach of treating an entire population, rather than just those infected, has helped reduce, and in some cases even eliminate, the impact of some NTDs. Just last year, four countries in the Western Pacific Region eliminated lymphatic filariasis, an extremely painful and disfiguring disease transmitted by mosquitos that can cause swelling of the limbs and genitals. In the Americas, onchocerciasis, also known as river blindness, has been eliminated from all but one region on the border of Venezuela and Brazil. Millions of people are now able to live free from disability and unnecessary suffering.
But efforts to control other NTDs lag. Rates of schistosomiasis, also known as “snail fever,” have increased and the major anthelminthic medicines have so far not had an impact on reducing the global burden of hookworm due to variable efficacy and high rates of reinfection.
New tools such as vaccines have the potential to support greater health outcomes in the most cost-effective manner possible for diseases that cannot be eliminated through treatment alone.
At Sabin, we are leading efforts to develop vaccines to combat NTDs affecting the world’s poorest people. Among them is a vaccine candidate for schistosomiasis that is currently in clinical trials. Genital schistosomiasis can create additional health risks, as women with the disease are three to four times more likely to contract HIV. To make matters worse, there is a growing concern that drug resistance could increase. A schistosomiasis vaccine could not only help control the disease but also be a cost-effective tool for reducing HIV in Africa. Sabin is also developing vaccines for hookworm infection and Chagas disease, among others.
The evidence supporting expanded vaccine research and immunization efforts against NTDs is clear, but this effort needs greater support. Increased funding is needed in order to help accelerate the development and testing of new vaccines, advance products currently in development and create a sustainable path to deliver them to people in need worldwide. Greater investment today will lay the foundation for vaccines to tackle neglected tropical diseases.
Photo by Anna Grove.