昭通市地处云、贵、川三省结合部，自1986年实施计划免疫以来，儿童免疫接种率达到了85％目标，但1996-1997年春的麻疹暴发流行中，仍以小年龄组发病为主，其中1岁内病例中60％的无免疫史；在6次12轮的预防脊髓灰质炎（脊灰）强化服苗中，自查接种率均在90％以上，但在集镇随机 Zhaotong City is located in the junction of Yunnan, Guizhou and Sichuan provinces. Since the implementation of the planned immunization program in 1986, the immunization coverage rate has reached 85%. However, in the epidemic of measles in the period of 1996-1997, the incidence of measles in the spring of 1996-1997 was still dominated by the younger age group , Of which 60% had no history of immunization in the case of 1-year-old; in 6 rounds of 12 rounds of prevention of poliomyelitis (poliomyelitis), the self-examination inoculation rates were above 90%