Rabies Vaccine Freed of the Factor Causing Allergic Encephalitis

Abstract

The factor of brain tissue responsible for the production of allergic encephalitis of guinea pigs can be extracted from rabies vaccine by the use of [image]/10 Ca acetate. The resulting partially purified vaccines are highly antigenic and contain about 50% of the original total N and only 0.005% Ca. This vaccine failed to produce allergic encephalitis in guinea pigs as evidenced both by clinical and pathological examination. It is presumed that such rabies vaccine will not produce postvaccinal paralysis in humans. The technique is as follows: (1) Suspension of dried, benzene ether-extracted rabies antigen in dist. H2O; (2) Extraction with 1 vol. of [image]/10 Ca acetate at 5[degree]C for 2 hrs.; (3) Centrifuge or filter mixture and resuspend insoluble material in 1 volume distilled H2O; (4) Separate insoluble material and resuspend it in water or saline. This is the finished, "washed" vaccine.