Sudden death in the first 2 years of life following immunization in the Republic of Korea.
BACKGROUND
Because the peak age for incidence of sudden deaths in infancy temporally coincides with the age of infant primary immunization, some have raised the question as to whether immunization is a risk factor for sudden death in infancy. Recent occurrence of two sudden deaths in infants in Korea has renewed concerns about the causal association between immunization and sudden deaths in infants.


METHODS
We carried out a retrospective review of data from the Korea Centers for Disease Control and Prevention Adverse Events Following Immunization Surveillance System and Vaccine Compensation programs.


RESULTS
From 1994 to 2011, a total of 45 cases of sudden deaths in the first 2 years of life following immunization were reported in Korea. The causes of death were classified as follows: infectious diseases (n= 13); accidental injuries (n= 7); congenital abnormalities (n= 2); and malignancy (n= 1). Of 20 sudden deaths in infancy, nine deaths met Brighton Collaboration case definition level I and II, and therefore were classified as possible sudden infant death syndrome cases. Hepatitis B vaccine (n= 13) was the most frequent vaccine with temporal association with sudden deaths in the first 2 years of life.


CONCLUSIONS
Few sudden deaths in the first 2 years of life following immunization have been reported, despite the use of universal immunization in Korea. The majority of deaths in infancy did not meet case definition for sudden infant death syndrome. Encouraging investigators to perform thorough investigation, including postmortem autopsy and death scene examination, may promote data comparability and provide guidance on decision-making in the vaccine-safety monitoring and response system in Korea.
Division of Vaccine Preventable Disease Control and National Immunization Program, Korea Centers for Disease Control and Prevention, Seoul, Korea. choeyj@yahoo.com
Young June
YJ
Choe
Jong-Hee
JH
Kim
Hyun Jin
HJ
Son
Geun-Ryang
GR
Bae
Duk-hyoung
DH
Lee
D002675:Child, Preschool; D003645:Death, Sudden / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007114:Immunization / Q000009:adverse effects* / Q000401:mortality; D015994:Incidence; D007223:Infant; D007226:Infant Mortality / Q000639:trends; D008297:Male; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies