Abstract: Objective To analyze the occurrence features of the active surveillance of adverse events following immunization (AEFI) in Tianjin, and evaluate the sensitivity of passive surveillance systems over the same period. Methods The layered eight vaccination clinics of four counties were selected as active surveillance points. The data of active surveillance AEFI were collected through telephone investigation in 2011-2013. The data of passive surveillance was collected through the national AEFI information management system. The descriptive methodology and chi square test were used. Results A total of 235 cases were collected through active surveillance in 2011-2013. The AEFI incidence rate was 718.70 per 100 000 doses， no difference in the incidence between three years（χ2=5.07). A total of 4164 cases were collected through passive surveillance. The incidence rate was 34.09 per 100 000 doses， the incidence increased year by year（χ2=572.02， P < 0.05). In active surveillance cases, 95.32% was the common vaccine reaction, 3.83% was the rare vaccine reaction, no serious vaccine reaction. In passive surveillance cases, the common vaccine reaction, the rare vaccine reaction were 85.09% and 13.32%. The serious vaccine reaction was found in 44 cases. Conclusion The more slightly common vaccine reaction can be found by active surveillance. The sensitivity of Tianjin passive surveillance system is increasing year by year, which can meet the requirements for job. The classification and diagnostic criteria of the serious vaccine reaction need to be established.

Key words: vaccines, adverse events following immunization, active surveillance, passive surveillance, Tianjin