Nonfatal demyelinating encephalomyelitis induced by coronavirus (JHM strain) infection in mice

C3H mice infected intravenously with the JHM strain of coronavirus showed high incidence of demyelination (44.8%) and low incidence of encephalitis-induced mortality (6.9%). High titers of virus were detectable in the brain and liver of mice only during the first 3 to 12 days of infection (10(3) and 10(4) PFU/g, respectively). Most of the animals recovered from the first phase of disease and some (11.1%) came down with paralysis 6 to 7 weeks after the infection, with no histological changes or virus detectable in their tissues.