Oral Peptide Vaccine against Hookworm Infection: Correlation of Antibody Titers with Protective Efficacy

Approximately 0.4 billion individuals worldwide are infected with hookworm. An effective vaccine is needed to not only improve the health of those affected and at high risk, but also economic growth in disease-endemic areas. ideal anti-hookworm therapeutic strategy for mass administration a stable orally administered vaccine. Oral vaccines advantageous as they negate need trained medical staff do require strict sterility conditions. Vaccination, therefore, can be carried out significantly reduced cost. One most promising current antigenic targets hookworm development aspartic protease digestive enzyme (APR-1). Antibody-mediated neutralization APR-1 deprives worm nourishment, leading burdens vaccinated hosts. Previously, we demonstrated that, when incorporated into delivery systems, APR-1-derived p3 epitope (TSLIAGPKAQVEAIQKYIGAEL) was able greatly reduce (≥90%) BALB/c mice; however, multiple, large doses were required. Here, investigated variety p3-antigen conjugates optimize antigen establish immune response/protective efficacy relationships. We synthesized, purified, characterized four peptide-based candidates with: (a) lipidic (lipid core peptide (LCP)); (b) classical polymeric (polymethylacrylate (PMA)); (c) novel (polyleucine branched or linear arrangement, BL10 LL10, respectively) groups self-adjuvanting moieties. LL10 induced highest serum anti-p3 anti-APR-1 IgG titers. Upon challenge rodent hookworms, significant reduction burden observed mice immunized LL10. APR-1-specific titers correlated reduction. Thus, provide first vaccine-triggered response-protection relationship infection.