Corona- and related viruses are important human and animal pathogens that also serve as models for other viral-mediated diseases. Interest in these pathogens has grown tremendously since the First International Symposium was held at the Institute of Virology and Immunobiology of the University of Wiirzburg, Germany. The Sixth International Symposium was held in Quebec City from August 27 to September I, 1994, and provided further understanding of the molecular biology, immunology, and pathogenesis of corona-, toro-, and arterivirus infections. Lectures were given on the molecular biology, pathogenesis, immune responses, and development of vaccines. Studies on the pathogenesis of coronavirus infections have been focused mainly on murine coronavirus, and mouse hepatitis virus. Neurotropic strains ofMHV (e.g., JHM, A59) cause a demyelinating disease that has served as an animal model for human multiple sclerosis. Dr. Samuel Dales, of the University of Western Ontario, London, Canada, gavea state-of-the-art lecture on our current understanding of the pathogenesis of JHM-induced disease.