Hookworm InfectionPhase 1NCT01940757
Experimental Infection of Hookworm-naïve Adults With Dermally-applied Infectious Necator Americanus Hookworm Larvae
A Phase 1 study testing Necator americanus Hookworm Larvae in people with Hookworm Infection, run by Baylor College of Medicine at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Hookworm Infection
- What is being tested?
- Necator americanus Hookworm Larvae
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 35 participants
- Where
- 1 siteUnited States
- Study dates
- Jan 2015to Dec 2027
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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.
Who cannot join
- 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).
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- 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.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
George Washington University Medical Faculty Associates
Washington D.C., District of Columbia, 20037
Study Coordinator, 2029941599, gwvru@gwu.edu
Aimee Desrosiers, PA
About this study
Official title: An Experimental Infection Study of Dermally-applied Infectious Necator Americanus Hookworm Larvae in Hookworm-naïve Adults
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.
Read the detailed description
Open-label, dose-escalation clinical study in healthy, hookworm-naïve adults:
- Study site: George Washington Medical Faculty Associates, Washington, DC
- Number of participants: up to 35 in 3 cohorts
In Cohort 1, ten (10) volunteers will receive an inoculum of 25 infectious Necator americanus larvae. In Cohort 2, ten (10) volunteers will receive an inoculum of 50 infectious Necator americanus larvae. In the optional Cohort 3, fifteen (15) volunteers will receive an inoculum of 75 infectious Necator americanus larvae.
The cohorts will be enrolled in a staggered fashion with safety data assessed prior to larval dose escalation. Cohort 2 will be inoculated no earlier than 8 weeks after the last volunteer is inoculated in Cohort 1. The optional Cohort 3 will be inoculated no sooner than 8 weeks after the last volunteer is inoculated in Cohort 2. Cohort 3 will be enrolled only if the tolerability of the experimental infection of Cohort 2 is acceptable and does not result in significant adverse events.
Within each cohort, after Study Day 70, but before Study Day 77, up to 5 volunteers will undergo capsule endoscopy in order to visualize and count adult N. americanus hookworms residing in the intestine. Informed consent for capsule endoscopy will be obtained separately from the primary study, and agreement or refusal will not impact on a subject's eligibility to enroll or continue participation in the primary study.
Three months after larval administration, or at the time of study withdrawal, all participants will receive a 3-dose treatment of albendazole (400 mg per dose) for clearance of experimental infection.
- Larval inoculum schedule: Study Day 0 (single application)
- Route: applied to intact skin on the volar aspect of forearm
- Doses of N. americanus Larval Inoculum to be tested: 25, 50 and 75 infectious larvae (high dose optional)
- Study duration: 6 months per study participant; total duration of the study estimated at approximately 13 months
- Anthelmintic treatment: 3 months post larval inoculum, or at study withdrawal, 3-dose treatment with 400 mg albendazole
- Conditions
- Hookworm Infection
- Being tested
- Necator americanus Hookworm Larvae
- Keywords
- Necator americanus, Hookworm Infection, Experimental challenge infection
- Medical subject headings
- Hookworm Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Necator americanus Hookworm LarvaeBiological
Also called Na-L3
Infectious larvae of the human hookworm Necator americanus
| Study group | Role | What they receive |
|---|---|---|
| Cohort 1 (25 Necator americanus Hookworm Larvae) | Experimental | 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. Receives: Biological: Necator americanus Hookworm Larvae |
| Cohort 2 (50 Necator americanus Hookworm Larvae) | Experimental | 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. Receives: Biological: Necator americanus Hookworm Larvae |
| Cohort 3 (75 Necator americanus Hookworm Larvae) | Experimental | 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. Receives: Biological: Necator americanus Hookworm Larvae |
What is being measured
The primary outcome is the main question the study is designed to answer.
Study product-related adverse events
Frequency of study product-related adverse events, graded by severity, for different doses of N. americanus Larval Inoculum.
Measured: Up to 6 months after dosing
Secondary outcomes (2)
Fecal egg counts
To determine the dose of N. americanus Larval Inoculum that generates the highest fecal egg counts, measured by fecal microscopy.
Measured: Up to Study Day 101
Number of adult hookworms in feces post-treatment
To compare the N. americanus Larval Inoculum dose received with the number of adult worms present in the gut, as determined by capsule endoscopy.
Measured: Study Days 87-101
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Sep 2013 (estimated)
- Study startJan 2015
- Primary completionDec 2027 (estimated)
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Hookworm InfectionStudies of the same condition, open and under way.
- More trials run by Baylor College of MedicineThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 35 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Baylor College of Medicine
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Maria Elena Bottazzi PhD, Baylor College of Medicine
- Investigators
- David J Diemert, MD, Principal investigator, George Washington University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01940757
- Sponsor's protocol ID
- SVI-CH-01
- Status last verified
- May 2026
- First submitted
- 9 Sep 2013
- Last updated
- 18 May 2026
- Results posted
- No
- Data monitoring committee
- Yes
Publications
Diemert D, Campbell D, Brelsford J, Leasure C, Li G, Peng J, Zumer M, Younes N, Bottazzi ME, Mejia R, Pritchard DI, Hawdon JM, Bethony JM. Controlled Human Hookworm Infection: Accelerating Human Hookworm Vaccine Development. Open Forum Infect Dis. 2018 Apr 19;5(5):ofy083. doi: 10.1093/ofid/ofy083. eCollection 2018 May.
PubMed 29780848
Study at a glance
From the registry record, last updated by the sponsor on 18 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Experimental Infection Study of Dermally-applied Infectious Necator Americanus Hookworm Larvae in Hookworm-naïve Adults
- ClinicalTrials.gov ID
- NCT01940757
- Acronym / sponsor ID
- SVI-CH-01
- Conditions
- Hookworm Infection
- Keywords
- Necator americanus, Hookworm Infection, Experimental challenge infection
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 35 participants (estimated)
- Lead sponsor
- Baylor College of MedicineUniversity, hospital or other
- Study start
- Jan 2015 (actual)
- Primary completion
- Dec 2027 (estimated)
- Study completion
- Dec 2027 (estimated)
- First posted
- 12 Sep 2013 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
Open-label, dose-escalation clinical study in healthy, hookworm-naïve adults:
- Study site: George Washington Medical Faculty Associates, Washington, DC
- Number of participants: up to 35 in 3 cohorts
In Cohort 1, ten (10) volunteers will receive an inoculum of 25 infectious Necator americanus larvae. In Cohort 2, ten (10) volunteers will receive an inoculum of 50 infectious Necator americanus larvae. In the optional Cohort 3, fifteen (15) volunteers will receive an inoculum of 75 infectious Necator americanus larvae.
The cohorts will be enrolled in a staggered fashion with safety data assessed prior to larval dose escalation. Cohort 2 will be inoculated no earlier than 8 weeks after the last volunteer is inoculated in Cohort 1. The optional Cohort 3 will be inoculated no sooner than 8 weeks after the last volunteer is inoculated in Cohort 2. Cohort 3 will be enrolled only if the tolerability of the experimental infection of Cohort 2 is acceptable and does not result in significant adverse events.
Within each cohort, after Study Day 70, but before Study Day 77, up to 5 volunteers will undergo capsule endoscopy in order to visualize and count adult N. americanus hookworms residing in the intestine. Informed consent for capsule endoscopy will be obtained separately from the primary study, and agreement or refusal will not impact on a subject's eligibility to enroll or continue participation in the primary study.
Three months after larval administration, or at the time of study withdrawal, all participants will receive a 3-dose treatment of albendazole (400 mg per dose) for clearance of experimental infection.
- Larval inoculum schedule: Study Day 0 (single application)
- Route: applied to intact skin on the volar aspect of forearm
- Doses of N. americanus Larval Inoculum to be tested: 25, 50 and 75 infectious larvae (high dose optional)
- Study duration: 6 months per study participant; total duration of the study estimated at approximately 13 months
- Anthelmintic treatment: 3 months post larval inoculum, or at study withdrawal, 3-dose treatment with 400 mg albendazole
Study design
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Cohort 1 (25 Necator americanus Hookworm Larvae) | Experimental | Biological: Necator americanus Hookworm LarvaeA dose of 25 Necator americanus Hookworm Larvae, administered via a sterile absorbent pad fixed with a transparent adhesive dressing for at least 1 hour. |
| Cohort 2 (50 Necator americanus Hookworm Larvae) | Experimental | Biological: Necator americanus Hookworm LarvaeA dose of 50 Necator americanus Hookworm Larvae, administered via a sterile absorbent pad fixed with a transparent adhesive dressing for at least 1 hour. |
| Cohort 3 (75 Necator americanus Hookworm Larvae) | Experimental | Biological: Necator americanus Hookworm LarvaeA dose of 75 Necator americanus Hookworm Larvae, administered via a sterile absorbent pad fixed with a transparent adhesive dressing for at least 1 hour. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- 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.
Key exclusion criteria (24 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Necator americanus Hookworm LarvaeAlso: Na-L3Infectious larvae of the human hookworm Necator americanus | Biological | Cohort 1 (25 Necator americanus Hookworm Larvae), Cohort 2 (50 Necator americanus Hookworm Larvae), Cohort 3 (75 Necator americanus Hookworm Larvae) |
Primary outcome
Study product-related adverse events
Time frame: Up to 6 months after dosing
Frequency of study product-related adverse events, graded by severity, for different doses of N. americanus Larval Inoculum.
2 secondary outcomes
Fecal egg counts
Time frame: Up to Study Day 101
Number of adult hookworms in feces post-treatment
Time frame: Study Days 87-101
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 May 2026.
- Derived from this study: PubMed 29780848Diemert D, Campbell D, Brelsford J, Leasure C, Li G, Peng J, Zumer M, Younes N, Bottazzi ME, Mejia R, Pritchard DI, Hawdon JM, Bethony JM. Controlled Human Hookworm Infection: Accelerating Human Hookworm Vaccine Development. Open Forum Infect Dis. 2018 Apr 19;5(5):ofy083. doi: 10.1093/ofid/ofy083. eCollection 2018 May.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
David J Diemert, MD principal investigator
George Washington University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Necator americanus Hookworm Larvae in people with Hookworm Infection, run by Baylor College of Medicine at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 24 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 18 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Study Coordinator ((202) 994-1599, gwvru@gwu.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Study product-related adverse events (time frame: Up to 6 months after dosing). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01940757, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 May 2026.