Study of Na-ASP-2 Human Hookworm Vaccine in Healthy Adults Without Evidence of Hookworm Infection

The primary objective of this clinical trial is to determine the safety and tolerability of the Na-ASP-2 Hookworm Vaccine in healthy subjects following the administration of 3 intramuscular (IM) injections of the vaccine over 16 weeks using 3 different doses. The secondary objective is to make a preliminary evaluation of the immunogenicity of each of the 3 doses of the vaccine in healthy volunteers.

There is an urgent need for new tools to control human hookworm infection and to reduce its burden of disease in developing countries. This is especially true for children and women of reproductive age who represent populations that are highly vulnerable to the effects of hookworm disease. Up to 65,000 deaths annually have been attributed to human hookworm infection. However, the mortality estimates of hookworm pale in comparison to global disease burden estimates. The primary approach to hookworm control worldwide has been the frequent and periodic use of benzimidazole anthelminthics for school-age children. However, school-based anthelminthic chemotherapy programs miss populations highly vulnerable to hookworm, including adolescent and adult women. In addition, high rates of hookworm re-infection occur within 4-12 months following anthelminthic chemotherapy, and there is evidence for diminished efficacy of benzimidazoles with frequent and periodic use, possibly because of emerging drug resistance. These concerns have prompted interest in developing alternative tools for hookworm control. Vaccination to prevent high intensity hookworm infection would alleviate the public health deficiencies of drug treatment alone.