Adverse events following immunization in Fujian province, 2012 – 2017: surveillance data analysis

  Objective  To analyze the incidence and characteristics of adverse events following immunization (AEFI) in Fujian province from 2012 to 2017 and to provide evidences for vaccination safety.

  Methods  We collected data on AEFI reported in Fujian province from January 1, 2012 to December 31, 2017 via National Immunization Program Information Management System and the data on yearly number of distributed doses of various vaccines in Fujian province from the individual immunization information system of Fujian province. Descriptive epidemiological method was used to analyze the distribution characteristics and related indicators of AEFI.

  Results  Totally 12 778 AEFIs were reported in the province during the period; about a half (47.89%) of the AEFIs were reported in Quanzhou, Xiamen and Fuzhou municipality and more AEFIs were reported in the second and third quarter than in the first and fourth quarter of a year. Among the reported AEFIs, 84.00% and 14.09% were common and rare vaccine reactions; the male to female ratio of the reported AEFIs was 1.71 : 1; and 83.80% of the reported AEFIs were small children aged ≤ 2 years. The overall estimated incidence rate of AEFI was 15.06 per 100 000 doses. The vaccines with the top first 3 estimated incidence rate of AEFI were diphtheria, tetanus and acellular pertussis, inactivated poliomyelitis and haemophilus influenzae type b conjugate combined vaccine (DTap-IPV/Hib, 54.52 per 100 000 doses), 23 valent pneumococcal polysaccharide vaccine (45.61 per 100 000 doses), and group A and C meningococcal and haemophilus type b conjugate vaccine (43.24 per 100 000 doses). Of the reported AEFIs, 80.83% occurred within one day after the vaccination and over three fifths (68.94%) occurred after the first dose vaccination. The most common symptoms for common reactions of the AEFIs were fever, local swelling and local indurations, while that for rare reactions was anaphylactic rash.

  Conclusion  The reported incidences of AEFI for all vaccines were not high than the expected. The sensitivity of the AEFI surveillance system needs to be improved.