[Requirements of rabbit-adapted swine fever vaccine]

Studies were conducted into the demands made on both harmlessness and effectiveness of SUVAC, a swine fever vaccine prepared from strain "C", a rabbit-adapted Chinese virus strain. The following findings were obtained: --The vaccine strain was attenuated to an extent by which it could be used without serum. --The vaccine was harmless even with immunodepressor action. Its immunogenicity was good, and live weight growth of the animals was not impaired. --The vaccine was harmless to the foetuses. --Very little virus was excreted by immunised pigs. --Vaccine attenuation was of high stability, and virulence was not even increased after six passages in pigs. --Between 50 and 100 immunising units were contained in one vaccine dose, and piglets immunised at the age of six weeks were protected after three months against an experimental infectino which was fatal to susceptible pigs. --Virus inoculated into PK 15-cell line proved negative in the first passage in response to immunofluorescence testing.