Investigation of adverse events following bacille Calmette-Guérin immunization using immunization safety surveillance system in Korea Centers for Disease Control and Prevention

PURPOSE: The report of adverse events following immunization (AEFI) in Korea has continued since 1994, and the most frequently reported cases of AEFI of Korea Centers for Disease Control and Prevention (KCDC) is bacille Calmette-Guérin (BCG). Meanwhile, various inoculation methods and strains have been used in the past 6 years in Korea. Therefore, we investigated AEFI of BCG by strain types and inoculation methods using immunization safety surveillance of KCDC. MATERIALS AND METHODS: We reviewed BCG AEFIs registered in the KCDC from January 2013 to June 2018. RESULTS: There were 336 AEFI cases during the period, and average time interval from vaccination to symptom onset was within 2 months. AEFI proportion was 6.4 cases per 100,000 doses for BCG percutaneous Tokyo strain, 41.6 cases per 100,000 doses of BCG intradermal Danish strain, and 25.9 cases per 100,000 doses of BCG intradermal Tokyo strain. Intradermal type was more reported AEFI than percutaneous type in the same strain. The most common adverse events were local reaction like BCG lymphadenitis and severe adverse reactions such as osteomyelitis or disseminated BCG disease were 0.1 to 0.2 cases per 100,000 doses which are correlated with the range of World Health Organization published AEFI rates. CONCLUSION: The AEFI reporting rate does not equal the actual proportion of AEFI occurrence. Because AEFI monitoring is a passive surveillance system, various factors might influence the number of events reported. Nevertheless, it is important to analyze BCG AEFI by vaccine strains and inoculation method using surveillance data of KCDC.