1. New Mexico Regional Primate Research Laboratory, New Mexico State University, Holloman Air Force Base, NM 88330.
2. Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322.
3. Controlled Release Division, Southern Research Institute, Birmingham, AL 35255.
4. Departments of Microbiology and Medicine, University of Alabama at Birmingham, Birmingham, AL 35294.