Experimental Infection of Hookworm-na ve Adults With Dermally-applied Infectious Necator Americanus Hookworm Larvae

  • End date
    Jun 10, 2021
  • participants needed
  • sponsor
    Baylor College of Medicine
Updated on 17 January 2021
Maria Zumer, PA
Primary Contact
George Washington University Medical Faculty Associates (7.1 mi away) Contact


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-nave 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.


Open-label, dose-escalation clinical study in healthy, hookworm-nave adults:

  • Study site: George Washington Medical Faculty Associates, Washington, DC
  • Number of participants: up to 30 in 3 cohorts of 10 volunteers each

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, ten (10) 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

Treatment Necator americanus Hookworm Larvae
Clinical Study IdentifierNCT01940757
SponsorBaylor College of Medicine
Last Modified on17 January 2021

Adding a note
adding personal notes guide

Select a piece of text and start making personal notes.

Similar trials to consider


Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

Sign up as volunteer


user name

Annotated by • 



Reply by • Private

Lorem ipsum dolor sit amet consectetur, adipisicing elit. Ipsa vel nobis alias. Quae eveniet velit voluptate quo doloribus maxime et dicta in sequi, corporis quod. Ea, dolor eius? Dolore, vel!

  The passcode will expire in None.

No made yet