Psychogenic illness following vaccination: exploratory study of mass vaccination against pandemic influenza A (H1N1) in 2009 in South Korea.
OBJECTIVE
Adverse events during mass vaccination campaigns have had a profoundly negative impact on vaccine coverage rates. The objective of the study was to identify the characteristics of reported psychogenic illness cases following mass vaccination that needed further interventions of the national immunization program.


METHODS
We collected documents that were submitted to the Korea Centers for Disease Control and Prevention for vaccine injury compensation, and analyzed cases of psychogenic illness following pandemic influenza A (H1N1) vaccination in 2009 which were confirmed by the Korean Advisory Committee on Vaccine Injury Compensation.


RESULTS
During the 2009-2010 influenza season, 13 million Koreans were vaccinated against pandemic influenza. Of 28 reported psychogenic illness cases following immunization, 25 were vaccinated through school-located mass immunization. Significant numbers of them were female adolescents (68%) or had underlying vulnerable conditions or emotional life stressors (36%). They required lengthy hospitalization (median, 7 days) and high medical costs (median, US $1,582 per case).


CONCLUSIONS
Health authorities and organizers of future mass vaccinations should be well aware of the possible occurrence of psychogenic illness, acknowledge their detailed characteristics, and take its economic burden into account to mitigate the risk of transmission of infectious diseases efficiently.
Division of Vaccine-Preventable Diseases Control and National Immunization Program, Korea Centers for Disease Control and Prevention, Cheongju, Korea.
Tae Un
0000-0001-8229-0977
TU
Yang
Division of Vaccine-Preventable Diseases Control and National Immunization Program, Korea Centers for Disease Control and Prevention, Cheongju, Korea.
Hee Jung
0000-0001-8783-4240
HJ
Kim
Division of Vaccine-Preventable Diseases Control and National Immunization Program, Korea Centers for Disease Control and Prevention, Cheongju, Korea.
Yeon Kyeong
0000-0003-4411-0941
YK
Lee
Division of Vaccine-Preventable Diseases Control and National Immunization Program, Korea Centers for Disease Control and Prevention, Cheongju, Korea.
Young-Joon
0000-0001-9697-4173
YJ
Park
Hysteria; Influenza vaccines; Mass vaccination; Psychophysiologic disorders; Students; Vaccination