Morbidity following viral challenge.

*Mice were inoculated with the specified dose via intracerebral inoculation in a volume of 30 ul. For group 5, virus was inactivated by exposure for 15 min to a UV light source and absence of infectious virus verified by plaque assay.**Mice were inoculated with the specified dose via intraperitoneal inoculation in a volume of 200 ul.***For interval studies, mice were infected with MV, rested for the indicated number of days, and then infected with LCMV.****Morbidity was determined by either weight loss greater than 20% and/or seizures, ataxia or persistent tremors.