Human hookworm vaccine containing hookworm larvae protects against infection.

2003 APR 9 - (NewsRx.com & NewsRx.net) -- BALB/c mice were successfully vaccinated against human hookworm (Necator americanus) by using N. americanus larvae.

According to recent research from England, "In this murine (BALB/c) model of necatoriasis, high levels of protection against challenge infection by Necator americanus larvae (n=300) were afforded by successive vaccinations at 14-day intervals, either subcutaneously or percutaneously, with gamma-irradiated N. americanus larvae (n=300). Percutaneous vaccination was significantly more effective than the subcutaneous route, with pulmonary larval burdens at three days post-infection being reduced by 97.8% vs 89.3%, respectively, after three immunizations (p

"No worms were recovered from the intestines of thrice vaccinated mice," reported N. Girod and collaborators at Nottingham Trent University and the University of Nottingham. "Two percutaneous vaccinations also reduced worm burdens, by 57% in the lungs and 98% in the intestines; p

The researchers found, "Lymphocytes from the axillary (skin-draining) lymph nodes of vaccinated mice, stimulated in vitro with concanavalin A, exhibited enhanced secretion of IL-4 protein and a higher IL-4/gamma-IFN protein ratio than lymphocytes from non-vaccinated animals. In vaccinated mice, levels of IgG1 and IgG3 (directed against larval excretory/secretory products) were elevated for the most part compared with those in non-vaccinated animals."

The investigators concluded, "These data demonstrate the successful vaccination of ...