1. Institute of Immunological Engineering, 142380 Lyubuchany, Russia, Departments of Pathology/Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas 77555, The Gamaleya Institute of Epidemiology and Microbiology, 123098 Moscow, Russia, and Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48824