Efficacy of Na-GST-1/Alhydrogel Hookworm Vaccine Assessed by Controlled Challenge Infection

Inclusion Criteria

• Males and non-pregnant females between 18 and 45 years, inclusive.
• Good general health as determined by means of the screening procedures1.
• Available for the duration of individual subject study participation (14 months).
• Willingness to participate in the study as evidenced by signing the informed consent document.
• Able to understand and comply with planned study procedures.

Exclusion Criteria

• Pregnancy as determined by a positive urine human choriogonadotropin (hCG) test (if female).
• Subject unwilling to use effective contraception for a minimum of 30 days prior to vaccination and up until documentation of clearance of hookworm infection post-CHHI (if female and not surgically sterile, abstinent from intercourse with a male partner, in a monogamous relationship with a vasectomized partner, at least 2 years post-menopausal, or determined otherwise by medical evaluation to be sterile).
• Currently lactating and breast-feeding or plans to breastfeed at any given time from the first study vaccination until clearance of hookworm infection post-CHHI (if female).
• Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, gastrointestinal, diabetes, or renal disease by history, physical examination, and/or laboratory studies.
• Has a diagnosis of schizophrenia, bipolar disease or other major psychiatric condition that would make compliance with study visits/procedures difficult (e.g., subject with psychoses or history of suicide attempt or gesture in the 3 years before study entry, ongoing risk for suicide).
• Known or suspected immunodeficiency or immunosuppression as a result of an underlying illness or treatment (causes for immunosuppression may include, but are not limited to, poorly-controlled diabetes mellitus, chronic liver disease, renal insufficiency, active neoplastic disease or a history of hematologic malignancy, connective tissue disease, organ transplant).
• Laboratory evidence of liver disease (alanine aminotransferase [ALT] greater than 1.25-times the upper reference limit).
• Laboratory evidence of renal disease (serum creatinine greater than 1.25-times the upper reference limit, or urine dipstick testing positive for glucose or more than trace protein).
• Laboratory evidence of hematologic disease (hemoglobin 10.8 x 103/mm3; absolute eosinophil count 800 μg/day of beclomethasone dipropionate or equivalent) or other immunosuppressive or cytotoxic drugs within 30 days of the volunteer's expected first vaccination in this study or planned use during the study.
• Receipt of a live vaccine within 4 weeks or a killed vaccine within 2 weeks prior to the volunteer's expected first vaccination in the study.
• Receipt of immunoglobin or other blood products (with exception of Rho D immunoglobulin) within 90 days of the planned first study vaccination.
• Known allergy to albendazole, amphotericin B or gentamicin.
• History of previous infection with hookworm or continuous residence for more than 6 months in a community where hookworm is endemic.
• Current or past scars, tattoos, or other disruptions of skin integrity at the intended site of larval application.
• Previous receipt of the Na-GST-1/Alhydrogel® hookworm vaccine.
• History of a surgical splenectomy.
• Pre-existing autoimmune or antibody-mediated diseases including but not limited to: systemic lupus erythematosis, rheumatoid arthritis, multiple sclerosis, Sjogren's syndrome, autoimmune thrombocytopenia; or laboratory evidence of possible autoimmune disease determined by a positive anti-dsDNA titer, positive rheumatoid factor, and/or proteinuria (greater than trace protein on urine dipstick testing).