Guillain-Barré syndrome following receipt of influenza A (H1N1) 2009 monovalent vaccine in Korea with an emphasis on Brighton Collaboration case definition.
BACKGROUND
In 2009-2010 season, with ongoing of influenza A (H1N1), employment of mass vaccination has generated concerns in issue of adverse events following immunization (AEFI). This study investigates the clinical and laboratory data of reported cases of Guillain-Barré syndrome (GBS) and Fisher syndrome (FS) following receipt of influenza A (H1N1) 2009 monovalent vaccine to the National Vaccine Injury Compensation Program (NVICP) in Korea, with all cases reviewed under case definition developed by Brighton Collaboration GBS Working Group.


METHODS
Retrospective review of medical records for all suspected cases of GBS ad FS following receipt of influenza A (H1N1) monovalent vaccine reported to NVICP from December 1, 2009, through April 28, 2010 was conducted. Additional analyses were performed for identification of levels of diagnostic certainty according to Brighton Collaboration case definition.


RESULTS
Of 29 reported cases, 22 were confirmed to meet Brighton criteria level 1, 2, or 3 for GBS (21) or FS (1). Of those, 2 (9.1%) met level 1, 9 (40.9%) met level 2, and 11 (50.0%) met level 3. The male to female ratio was 2:0 in cases with level 1, 8:1 in cases with level 2, and 3:8 in cases with level 3. The mean age was older in cases with level 1 (54.0 ± 26.9) than that of cases with level 2 (25.6 ± 22.8), and level 3 (13.6 ± 2.4, P=0.005). The median onset interval was longer in cases with level 1 (16 days) than that of cases that met level 2 (12.44 days), and 3 (1.09 days, P=0.019).


CONCLUSIONS
The Brighton case definition was used to improve the quality of AEFI data in Korea, and was applicable in retrospective review of medical records in cases with GBS and FS after influenza A (H1N1) vaccination. These findings suggest that standardized case definition was feasible in clarifying the AEFI data, and to further increase the understanding of possible relationship of influenza vaccine and GBS.
Division of Vaccine Preventable Disease Control and National Immunization Program, Korea Centers for Disease Control and Prevention, Osong Health Technology Administration Complex, Pepublic of Korea. choeyj@yahoo.com
Young June
YJ
Choe
Heeyeon
H
Cho
Geun-Ryang
GR
Bae
Jong-Koo
JK
Lee
D000293:Adolescent; D000328:Adult; D016907:Adverse Drug Reaction Reporting Systems; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D020275:Guillain-Barre Syndrome / Q000139:chemically induced*; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D007252:Influenza Vaccines / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D019846:Miller Fisher Syndrome / Q000139:chemically induced; D056910:Republic of Korea; D012189:Retrospective Studies; D014611:Vaccination / Q000009:adverse effects*; D055815:Young Adult
D007252:Influenza Vaccines