Inclusion Criteria:

• Males or females between 18 and 45 years of age, inclusive.
• Good general health as determined by means of the screening procedure.
• Willingness to participate in the study as evidenced by signing the informed consent document.

Exclusion Criteria:

• History of previous infection with hookworm.
• Prior extensive and continuous travel, work, or residence (> 1 month) in a hookworm-endemic region.
• Pregnancy as determined by a positive urine hCG test (if female).
• Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, or renal disease by history or physical examination.
• Behavioral, cognitive, or psychiatric disease that in the opinion of the investigator affects the ability of the volunteer to understand and cooperate with the study protocol.
• 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.
• Participation in an investigational vaccine or drug trial within 14 days of starting this study.
• Volunteer has had medical, occupational, or family problems as a result of alcohol or illicit drug use during the past 12 months.
• History of a severe allergic reaction or anaphylaxis.
• Known immunodeficiency syndrome.
• Use of corticosteroids (excluding topical or nasal) or immunosuppressive drugs within 30 days of starting this study.
• History of a surgical splenectomy.
• Extensive dermatitis precluding skin testing
• Current use of a beta blocker (oral or topical) or anti-histamine medication. A volunteer may participate in the study if they agree to withhold use of an anti-histamine for at least 5 days prior to application of the skin test.
• Use of a tricyclic anti-depressant within the past month.