ACTIVE IMMUNIZATION OF GUINEA PIGS WITH THE VIRUS OF EQUINE ENCEPHALOMYELITIS : II. IMMUNIZATION WITH FORMOLIZED VIRUS.

From a study by quantitative methods, the conclusion is reached that a resistance of high degree may be induced in guinea pigs and mice against experimental equine encephalomyelitis by means of formolized vaccines in which no active virus can be demonstrated. The induced resistance is not due to residual traces of active virus which might possibly have escaped detection in the formolized tissue preparations.