Halting harmful helminths: Vaccines and new drugs are needed to combat parasitic worm infections

More than 300 million people are infected each year with parasitic flatworms such as hydatid tapeworms and blood fluke schistosomes. The diseases caused by such parasitic helminths, including alveolar/cystic echinococcosis and hepatosplenic/urogenital schistosomiasis, are typically chronic but frequently deadly. They are among the 17 neglected tropical diseases listed by the United Nations World Health Organization, and infections by these flatworm pathogens cause ∼4 million disability-adjusted life years to be lost annually, although this vastly underestimates the true impact that such long-term and chronic illnesses can have (1). Historically considered restricted to the tropics and subtropics, suitable habitats for transmission of these parasites are now expanding into Europe (2), and conditions are right for similar expansions to other continents (3, 4). The lack of vaccines perpetuates the unsustainable over-reliance on single-drug chemotherapies, a potentially catastrophic situation unless new solutions are found.