INTRAPERITONEAL AND INTRACEREBRAL ROUTES IN SERUM PROTECTION TESTS WITH THE VIRUS OF EQUINE ENCEPHALOMYELITIS : II. MECHANISM UNDERLYING THE DIFFERENCE IN PROTECTIVE POWER BY THE TWO ROUTES.

Minute amounts of antiserum injected intraperitoneally protect against large doses of equine encephalomyelitis virus given intramuscularly or intraperitoneally in 12 to 15 day old mice. Antiserum given intraperitoneally with virus intracerebrally or intranasally results in little or no protection. These phenomena occur as well when serum-virus mixtures are injected at the different sites. The marked variation of the protective capacity of antiserum as thus displayed would appear to be dependent upon the differing pathways of progression of the virus from the site of injection to the central nervous system.