THE BIOLOGICAL PURIFICATION OF VACCINE EMULSIONS BY PENICILLIN

Abstract

The present communication furnishes a new method for the purification of smallpox vaccine emulsion by penicillin. Penicillin, when added in definite quantities, possesses an undeniable antibiotic power on most of the Gram-positive cocci and on the vegetative forms of certain anaerobic bacteria such as Clostridium perfringens and C. fallax found in the vaccine. By maintaining a threshold of penicillin (56 units per cc.), the spores of the above mentioned anaerobic microbes cannot grow. When the vaccine emulsion freed from penicillin is inoculated, new strains without any pathogenic properties can be subcultured. Penicillin has no effect on the vaccine virus. By this technique, the vaccine can be freed, in a few days, of its principal pathogenic microbes except from Gram-negative bacilli. In the emulsion thus treated, the periodic control of the penicillin titre is as necessary as the repeated tests made to establish the potency of the vaccine.