title: Adverse events following immunization (AEFI) with the novel influenza a (H1N1) 2009 vaccine: findings from the national registry of all vaccine recipients and AEFI and the passive surveillance system in South Korea.
abstract: This study characterized the adverse events following immunization (AEFI) with the  novel influenza A (H1N1) 2009 vaccine in Korea. Data on immunization and AEFI were collected  between October 27, 2009 and March 15, 2010 through the national immunization registry and passive  surveillance systems. The frequency of AEFI and serious adverse events (SAEs) were calculated  according to age, sex, priority group, and vaccine type. In 13,758,527 vaccine recipients aged 6  months or older, 2,530 AEFI were reported (18.4 per 100,000 immunizations). The AEFI reporting  rate was highest among people aged 10-19 years (29.6 per 100,000 immunizations) and was higher in  female recipients than in male recipients (20.0 versus 16.7 per 100,000 immunizations). Most AEFIs  were nonspecific systematic reactions that occurred within 24 h (77.4%) after vaccine administration.  A total of 178 vaccine-related SAEs were identified, and vaccine-related mortalities were not  reported. This study showed that the AEFI reporting rate after influenza A (H1N1) 2009 vaccinations  was relatively high, especially in the younger population. Mild systemic reactions accounted for  the majority of reported AEFI, and fatal SAEs were rare. This study also implied that passive  surveillance might be an efficient safety monitoring system that can detect relatively rare AEFI.
authors.affiliation: Division of VPD Control & NIP, Korea Centers for Disease Control & Prevention, Chungchungbuk-do, Korea.
authors.forename: Jong-Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Hee-Yeon
authors.initials: HY
authors.lastname: Cho
authors.forename: Karen A
authors.initials: KA
authors.lastname: Hennessey
authors.forename: Hoan Jong
authors.initials: HJ
authors.lastname: Lee
authors.forename: Geun Ryang
authors.initials: GR
authors.lastname: Bae
authors.forename: Hyeon Chang
authors.initials: HC
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology* / Q000472:pathogenicity; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000009:adverse effects*; D007251:Influenza, Human / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D056910:Republic of Korea / Q000453:epidemiology; D017678:Sex Distribution; D016019:Survival Analysis; D014611:Vaccination / Q000009:adverse effects* / Q000379:methods; D055815:Young Adult
chemical_list: D007252:Influenza Vaccines