Study of Na-APR-1 (M74)/Alhydrogel® Co-administered With Na-GST-1/Alhydrogel in Brazilian Adults

Inclusion Criteria: 1. Males or non-pregnant females between 18 and 45 years, inclusive. 2. Good general health as determined by means of the screening procedure. 3. Available for the duration of individual subject study participation (16 months). 4. Willingness to participate in the study as evidenced by signing the informed consent document. Exclusion Criteria: 1. Pregnancy as determined by a positive urine hCG (if female). 2. Subject unwilling to use reliable contraception (as described in Section 2.3.1) from 30 days prior to the first immunization and up until one month following the third immunization (if female and not surgically sterile, abstinent or at least 2 years post-menopausal, or determined otherwise by medical evaluation to be sterile). 3. Currently lactating and breast-feeding (if female). 4. Inability to correctly answer all questions on the informed consent comprehension questionnaire. 5. Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, diabetes, or renal disease by history, physical examination, and/or laboratory studies (a history of essential hypertension that is well controlled by medication will not be considered exclusionary.) 6. 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). 7. Known or suspected immunodeficiency. 8. Laboratory evidence of liver disease (alanine aminotransferase \[ALT\] greater than 1.25-times the upper reference limit). 9. Laboratory evidence of renal disease (serum creatinine greater than 1.25-times the upper reference limit, or more than trace protein or blood on urine dipstick testing with the exception of greater than trace blood detected in females during menses). 10. Laboratory evidence of hematologic disease (absolute leukocyte count \<3200/mm3; absolute leukocyte count \>10.8 x 103/mm3; hemoglobin \<11.4 g/dl \[females\] or \<12.1 g/dl \[males\]; or, platelet count \<130,000/mm3). 11. Serum glucose (random) greater than 1.2-times the upper reference limit. 12. Other condition that in the opinion of the investigator would jeopardize the safety or rights of a volunteer participating in the trial or would render the subject unable to comply with the protocol. 13. Participation in another investigational vaccine or drug trial within 30 days of starting this study. 14. Previous receipt of the Na-GST-1/Alhydrogel® hookworm vaccine. 15. Volunteer has had medical, occupational, or family problems as a result of alcohol or illicit drug use during the past 12 months. 16. History of a severe allergic reaction or anaphylaxis. 17. Severe asthma as defined by the need for daily use of inhalers or emergency clinic visit or hospitalization within the last 6 months. 18. Positive test for hepatitis B surface antigen (HBsAg). 19. Positive confirmatory test for HIV infection. 20. Positive confirmatory test for hepatitis C virus (HCV) infection. 21. Use of corticosteroids (excluding topical or nasal) or immunosuppressive drugs within 30 days of the volunteer's expected first vaccination in this study or planned use up to one month following the last vaccination. 22. Receipt of a live vaccine within past 4 weeks or a killed vaccine within past 2 weeks prior to the volunteer's expected first vaccination in the study. 23. History of a surgical splenectomy. 24. Receipt of blood products within the past 6 months. 25. Anti-Na-GST-1 IgE antibody level above 0.35 kUA/L by the ImmunoCAP method. 26. Anti-Na-APR-1 IgE antibody level above ELISA reactivity threshold.