猪瘟冻干活疫苗保护剂的研究（续报）

Studies On the Cryoprotectant for the Freeze-Dried Lapinized Hog Cholera Vaccine(continuous report)

应用耐温保护剂Ａ１或无硫脲Ａ１制成兔化猪瘟病毒冻干疫苗若干批。所有应用Ａ１作保护剂的产品都出现干缩现象，而应用无硫脲Ａ１的未出现。５批无硫脲Ａ１的疫苗经在３７℃中保存１５天或在２５℃保存１００天后，都能保护疫苗接种动物抵抗强毒攻击，此种保护力与规定标准一致，而应用Ａ１的对照疫苗达不到此项标准。

Abstract Batches of experimental freeze-dried cell-cultured lapinized hog choleravaccine were produced with cryprotectant either Al or thiurea-free Al. Shrink of vaccine appeared in all product with Al, but not so with thiourea-free Al. 5 batches of vaccine that had been produced with the thiourea-free Al and stored at 30℃ for 15 days or 25℃ for 100 days, protected the vaccinated animals against challenge with the virulent virus strain. These results were in keeping with the standard of the bioproducts regulation. The control batches of vaccine produced with the Al did not up to the standard.