对象选择①无伤寒史,三年内末接种伤寒、副伤寒甲乙菌苗(下称菌苗)者,3～55岁各年龄组男女各半;②未接种菌苗者为城市四个厂、校、幼儿园111人;两个农村302人;③接种菌苗者系1980年3～5月实施基础注射的四个村队526人。④共选择10个单位939人,作肥达氏试验1379人次。 Subjects selection ① no history of typhoid, within three years of vaccination at the end of typhoid, paratyphoid A and B vaccine (hereinafter referred to as vaccine), 3 to 55 age groups of men and women in each half; ② unvaccinated persons were four plants in the city, school , 111 in kindergarten; 302 in two rural areas; ③ Inoculated bacteriniae were 526 among the four village teams who had undergone basic injections from March to May 1980. ④ choose a total of 9 9 9 units, 1379 for Watson test.