Two-week-old mice inoculated with herpes virus on the pad of a hind foot regularly developed paralysis of the infected limb followed by paraplegia and encephalitis terminating fatally 5 or 6 days after inoculation.
Hyperimmune rabbit serum given intraperitoneally at the time virus was inoculated on the foot pad prevented the formation of an herpetic lesion of the foot pad. When the antiserum was given 12 hours after inoculation of the virus, a typical infection of the epithelium of the foot pad developed, but the virus was prevented from causing obvious signs of infection of the nervous system in many of the animals.
Amputation of the foot 2 hours after the inoculation of the virus prevented the paralysis of the hind leg. Some of the mice died of a delayed encephalitis. Amputation of the foot at 24 hours neither prevented nor delayed the sequence of paralysis of the hind leg, encephalitis, and death.
In order to study immune serum therapy of an infection of the nervous system uncomplicated by a peripheral focus of infection or by traumatic disturbance of the central nervous system, 2-week-old mice were inoculated on the foot pad, the infected feet were amputated 24 hours later, and the immune serum was administered at varying intervals thereafter.
Using litter mate controls and statistically significant numbers of mice, it was shown that hyperimmune rabbit serum, administered during the first one-third of the incubation period, retards and, in some cases, arrests the progress of herpetic infection within the nervous system.