[Analysis on death from adverse event following immunization surveillance system of Shandong Province during 2011-2016].

Objective To analyze the occurrence and death of Adverse Event Following Immunization (AEFI) in Shandong province. Methods Collecting the information of AEFI cases from 2011 to 2016, which were reported through the National AEFI Management System in Shandong province up to January 15, 2017. The autopsy reports of death following immunization were issued by the qualified institutions. The inoculation data from 2011 to 2016 was obtained through Immunization Information Management System of Shandong province. Chi-square test was used to compare the incidence rate of AEFI and mortality related to immunization among different time and age groups. Results A total of 189 864 512 doses of vaccine were administered in Shandong province during 2011-2016, the total number of AEFI cases was 89 973 and the incidence rate of AEFI was 473.88/1 000 000. The number of death cases was 52 and the mortality rate was 0.27/1 000 000. The incidence rate of AEFI from 2011 to 2016 respectively was 273.63/1 000 000, 405.22/1 000 000, 479.88/1 000 000, 545.13/1 000 000, 500.66/1 000 000, and 627.09/1 000 000 (P<0.001), respectively. The mortality rate from 2011 to 2016 was 0.17/1 000 000, 0.16/1 000 000, 0.25/1 000 000, 0.39/1 000 000, 0.26/1 000 000, and 0.40/1 000 000 (P=0.285), respectively.The mortality rates of HepB, BCG and IPV were the top three. There was statistical significance of the mortality rate among different month-old children (P<0.001). The highest mortality rate was<2 month-old (1.09/1 000 000), and the next was 4-5 month-old (0.54/1 000 000), and the lowest was ≥10 month-old (0.06/1 000 000). The mortality rate of spring (from February to April), summer (from May to July), autumn (from August to October) and winter (from November to January of next year) was 0.41/1 000 000, 0.16/1 000 000, 0.08/1 000 000 and 0.48/1 000 000 (P<0.001), respectively. Among 52 death cases, 26 cases were anatomized, including 3 rare vaccine reaction following immunization and 23 coincidental events; 26 cases were not anatomized, including 17 coincidental events and 9 unknown causes. Conclusion The AEFI mortality rate of<2 month-old, spring and winter, and the second dose was higher than else, which was similar to normal child mortality. Immunization did not increase the risk of death, and the most deaths following immunization were coincidental events. Key words: Vaccines; Vaccination; Mortality; Adverse event following immunization