Perspective: Prospects for Development of Vaccines against Human Helminth Infections

The global prevalence of infection with parasitic worms or helminths likely exceeds that of any other infection. One-third of the world's population is estimated to harbor infection with intestinal helminths (Trichuris trichuria, Ascaris lumbricoides, Strongyloides stercoralis, or hookworm) [1]; between 200 and 300 million people are believed to be infected with one of the three species of schistosomes (Schistosoma mansoni, Schisto-soma haematobium, Schistosoma japonicum) [2], and> 150 million are infected with one of the pathogenic:filarial parasites (Wuchereria bancrofti, Brugia malayi, Onchocerca volvulus, Loa loa) [3, 4]. The burden of helminth infection rests largely on the population of the developing world, where many persons carry infection with more than one of these parasites [5]. While nematode infection uncommonly leads to severe acute illness or death, a growing body of evidence indicates tha