Background: The human hookworm, Necator americanus, is a parasite that infects almost half a billion people worldwide. Although treatment is available, vaccination is favorable to combat the spread of this parasite due to its wide distribution and continuous reinfection cycle in endemic communities.
Methods: We have designed a lipopeptide oral delivery system using a B-cell epitope derived from the aspartic protease Na-APR-1 from N americanus, attached to a T-helper epitope. Lipopeptides were self-assembled into nanoparticles or entrapped in liposomes that were electrostatically coated with alginate and trimethyl chitosan polymer shields. The adjuvant-free vaccine candidates were orally administered to mice and generated a humoral immune response against both peptide antigen, and the parent protein in the hookworm gut.
Results: The vaccine candidates were evaluated in a rodent hookworm challenge model, resulting in up to 98% and 99% decreases in mean intestinal worm and egg burdens in immunized mice, respectively.
Conclusions: Lipopeptide survived the gastrointestinal conditions, induced humoral immune responses and drived protection against parasite challenge infection.
Keywords: Necator americanus; Nippostrongylus brasiliensis; hookworm; lipopeptide; oral vaccine.
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