The comparative testing of the immunogenic activity of vaccines produced with strain K cultured in cell cultures and rabbits has revealed that one vaccinal dose of the culture vaccine for pigs contains 1 000 reactogenic doses for rabbits and about 400 immunizing doses for pigs. In a vaccinal dose for pigs of a vaccine obtained from rabbits there are 400 reactogenic doses for rabbits and 100 immunizing doses for pigs. Swine fever-affected pigs treated with a vaccine of strain K, containing more than 100 immunizing doses per vaccinal dose, develop immunity that lasts not less than 12 months. Freeze-dried vaccines of strain K can be stored at ordinary refrigerator temperature in the course of one year, and at minus 20 to 30 degrees C--in the course of two years.