Recruiting
Phase 1

Observational Study

Sponsor:

Baylor College of Medicine

Code:

NCT01940757

Conditions

Hookworm Infection

Eligibility Criteria

Sex: All

Age: 18 - 45

Healthy Volunteers: Accepted

Interventions

Necator americanus Hookworm Larvae

Study Details

Brief summary:

An experimental hookworm infection model is being developed to provide early proof-of-concept that a hookworm vaccine targeting the blood-feeding pathway of adult hookworms is feasible and efficacious. The proposed model consists of vaccinating healthy, hookworm-naïve adults with a candidate hookworm vaccine, followed by challenging them with the investigational product, Necator americanus Larval Inoculum to assess the effect of vaccination on infection. The first proposed study will be a feasibility study that will consist of administering different doses of the Necator americanus Larval Inoculum to healthy adult volunteers to determine the optimal dose (i.e., number of infectious larvae) that is safe, well-tolerated and results in consistent infection.

Conditions

Hookworm Infection

Study ID

NCT01940757

Start date

Jan, 2015

Status verified date

May, 2026

Completion date

Dec, 2027

Anticipated

Primary completion date

Dec, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 45

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Males or females between 18 and 45 years, inclusive.
  • Good general health as determined by means of the screening procedure.
  • Available for the duration of the trial (6 months).
  • Willingness to participate in the study as evidenced by signing the informed consent document.

Exclusion Criteria:

  • Pregnancy as determined by a positive urine human choriogonadotropin (hCG) (if female).
  • Participant unwilling to use reliable contraception methods while participating in the study (if female and not surgically sterile, abstinent or at least 2 years post-menopausal).
  • Currently lactating and breast-feeding (if female).
  • Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, diabetes, or renal disease by history, physical examination, and/or laboratory studies.
  • Known or suspected immunodeficiency.
  • 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 more than trace protein or blood on urine dipstick testing).
  • Laboratory evidence of hematologic disease (hemoglobin <11.5 g/dl \[females\] or <12.5 g/dl \[males\]; absolute leukocyte count <3.6 or >10.7 x 103/mm3; absolute neutrophil count \[ANC\] <1.7 x 103/mm3; absolute lymphocyte count <0.7 x 103/mm3; or platelet count <140 x 103/mm3).
  • History of iron deficiency anemia.
  • History of hypoalbuminemia.
  • Laboratory evidence of a coagulopathy (PTT or PT INR greater than 1.1-times the upper reference limit).
  • Serum glucose (random) greater than 1.2-times the upper reference limit.
  • 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.
  • 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.
  • Severe asthma as defined by the need for daily use of inhalers or emergency clinic visit or hospitalization within 6 months of the volunteer's expected Day 0 of the study.
  • Positive ELISA for hepatitis B surface antigen (HBsAg).
  • Positive confirmatory test for HIV infection.
  • Positive confirmatory test for hepatitis C virus (HCV) infection.
  • Use of corticosteroids (excluding topical or nasal) or immunosuppressive drugs within 30 days of the volunteer's expected Day 0 of 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 Day 0 of the study.
  • Receipt of blood products within the past 6 months.
  • Known allergy to amphotericin B or gentamicin.
  • History of previous infection with hookworm or residence for more than 6 months in a hookworm-endemic area.

Study Design

Enrollment

35 participants

Anticipated

Allocation

Non randomized

Intervention Model

Parallel Assignment

Primary purpose

Other

Interventions and Outcome Measures

Arms

experimental: Cohort 1 (25 Necator americanus Hookworm Larvae)

A dose of 25 Necator americanus Hookworm Larvae, administered via a sterile absorbent pad fixed with a transparent adhesive dressing for at least 1 hour.

experimental: Cohort 2 (50 Necator americanus Hookworm Larvae)

A dose of 50 Necator americanus Hookworm Larvae, administered via a sterile absorbent pad fixed with a transparent adhesive dressing for at least 1 hour.

experimental: Cohort 3 (75 Necator americanus Hookworm Larvae)

A dose of 75 Necator americanus Hookworm Larvae, administered via a sterile absorbent pad fixed with a transparent adhesive dressing for at least 1 hour.

Interventions

Necator americanus Hookworm Larvae

Infectious larvae of the human hookworm Necator americanus

Primary outcome measure

  • Study product-related adverse events [ Time Frame: Up to 6 months after dosing ]

Central Contacts and Locations

Central contacts

Study Coordinator

(202) 994-1599gwvru@gwu.edu

Locations

George Washington University Medical Faculty Associates

Recruiting

Washington D.C., District of Columbia, United States, 20037

Contacts

Study Coordinator

2029941599gwvru@gwu.edu

More Information

Sponsor

Baylor College of Medicine

Last update posted

May 18, 2026

Last verified

May, 2026

Keywords

  • Necator americanus
  • Hookworm Infection
  • Experimental challenge infection

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Baylor College of Medicine on 2026-05-18.