Tu213 - Developing a Vaccine for Dracunculus Medinensis (Guinea Worm)

Vishal Khatri, PhD – Biomedical Sciences – University of Illinois; Ramaswamy Kalyanasundaram, DVM, PhD – Professor, Biomedical Sciences, University of Illinois

Abstract Text: One of the major focus of our laboratory is to develop vaccines for neglected tropical helminth parasitic infection. Dracunculiasis, popularly known as Guinea Worm Disease (GWD), is a tropical parasitic infection of humans caused by the nematode, Dracunculus medinensis and the infection is transmitted through drinking water. Migration and emergence of female worms through the skin results in blisters complicated with secondary infections. There are no effective treatment options for GWD. However, eradication of human dracunculiasis is nearly achieved by providing safe drinking water, prompt symptomatic treatment of infected individuals and preventing contamination of water sources. However, several reports demonstrated that dracunculiasis is a zoonotic infection with mainly dogs as carrier hosts. There is no treatment or vaccine to control GWD in dogs. Thus, the major focus of this study was to develop a vaccine for dog dracunculiasis. Genome of D. medinensis is available, but only very few genes are annotated. Based on previous reports from other helminths that are closely related to D. medinensis, we identified, cloned and expressed three antigens (DmHSP, DmTPX and DmCol-4) of D. medinensis. Homolog of all three antigens were previously shown to be excellent vaccine candidates against other closely related parasites. We also prepared a trivalent fusion protein of all three antigens as DmHTC. Immunogenicity studies in a mouse model showed that all three antigens and the fusion protein are highly immunogenic with IgG titers (>1:20,000) and antigen specific memory T cells. Challenge studies will determine the vaccine efficacy of the identified candidates.