Responses of mice susceptible or resistant to lethal infection with mouse hepatitis virus, strain JHM, after exposure by a natural route.

CF1 mice were resistant and BALB/cByJ mice were susceptible to the lethal effects of MHV-JHM infection after intranasal inoculation. Virus was recovered rarely from tissues of CF1 mice. In contrast, MHV-JHM was pantropic in BALB/cByJ mice. The peak systemic interferon response of Balb/cByJ mice occurred 30 hours later than that of CF1 mice. Exogenously administered interferon resulted in partial protection of Balb/cByJ mice challenged with MHV-JHM. Prior immunization of susceptible mice with MHV-JHM protected against challenge with homologous or heterologous (MHV-3) virus.