Guinea pigs and calves were inoculated with bovine paratyphus living vaccine prepared from attenuated ?S. dublin? strain (STM8002 550), then challenged with 2 MLD of the virulent ?S. dublin? strain (S8002) and ?S.

• 用都柏林沙门氏菌弱毒株（STM8002－550）制造的牛副伤寒活菌苗免疫豚鼠和牦犊牛，15d后用2个最小致死量（MLD）的都柏林沙门氏菌原始强毒株（S8002）和病牛沙门氏菌强毒株（C79－88）分别进行攻击。