The Use of Human Volunteers in the Collection of the Third Stage Larva of Onchocerca volvulus: Guidelines for the Edna McConnell Clark Foundation

by Jeffrey Mecaskey

I) These guidelines were developed by the Oncho Task Force at a meeting held in New York City on 29, July 1993. The following individuals participated in their development: John E. Donelson, Joseph A. Cook, Brian O. L. Duke, Jeffrey Mecaskey, Eric A. Ottesen, and Cathy Steel, the Oncho Task Force Coordinator. Recognizing the important distinction between infection and disease, the impetus for this policy is to prevent clinical disease while recognizing that definitive treatment for infection is currently unavailable. The purpose of the guidelines is to insure the safety and well being of human volunteers involved in the collection of the research resource, the third stage larvae of O. volvulus.

II) Research for a vaccine against onchocerciasis is dependent upon a steady and secure supply of the third stage larvae (L3's) of O. volvulus. In the effort to create a protective vaccine, L3's are critical for identifying and evaluating candidate antigens, and they are necessary for evaluating those antigens in animal screening systems. To date, scientists have not successfully replicated the complete life cycle of L3's in captivity. Consequently, infected human volunteers have become an integral aspect of L3 collection and production. Recognizing the ethical imperative to do no harm, the following outlines the Foundation's policy with respect to the use of human volunteers in the production of O. volvulus L3's.

III) Volunteer donors are by definition individuals infected by O. volvulus, with relatively high levels of microfiladermia. Although the Foundation's support for immunology research for a vaccine against onchocerciasis requires a supply of L3's, the Foundation cannot support work that could adversely affect the health of any human volunteers.

A) The period of employment with remuneration of any human volunteer will be limited to a period of no more than 6 months. After this time, the volunteer will be taken off the payroll and will be encouraged to take treatment with ivermectin.

B) Volunteers will be again eligible to receive remuneration and to assist in the collection of L3's approximately 9 to 12 months post-treatment, after he/she has reached an appropriate level of microfiladermia.

C) Through the tenure of their service, volunteers will be clinically examined at least 3 times over each 6 month term of service and will receive medical treatment as indicated. If signs of onchocerca-induced pathology are observed, volunteers will be taken off the payroll and encouraged to take treatment with ivermectin.