(P-110) Signal Detection of Zoster Vaccine Adverse Event in Elderly Using Korea Adverse Event Reporting System Database (KAERS)

Background: Herpes zoster’s incidence rate has been increased recently, leading to the high burden of disease due to complications (ophthalmic, vascular, visceral, and neurological), especially in the elderly. Therefore, zoster vaccination is being conducted over the age of 65 elderly, and it is important to identify adverse events. Although the zoster vaccine was launched in Korea in 2012, adverse events following immunization (AEFI) studies are insufficient.

Objectives: The object of this study was to detect the signals of the zoster AEFIs using the Korea Adverse Events Reporting System database.

Methods: We detected signals of the AEFIs of zoster vaccine (WHO-ATC; J07BK02 and J07BK03) by data mining using the Korea Institute of Drug Safety & Risk Management-Korea Adverse Event Reporting System database from January 2005 to December 2019. We used the tree-based scan statistic (TBSS) and two disproportionality analysis for signal detection: proportional reporting ratio (PRR) and information component (IC). The disproportionality analysis was calculated based on the reported WHO-ART preferred terms (PT). TBSS was calculated the log-likelihood ratio based on the reported all hierarchical level term. In this study, we defined a signal that satisfied all the disproportional analysis indices or satisfied TBSS. We compared detected safety signals and AEs from drug labels in South Korea, United States, and Japan.

Results: Among the total of 36,211 vaccine ICSRs in the KAERS database, 2,010 ICSRs of zoster vaccines over the 65 years old. Ten signals were satisfying the disproportionality analysis indices, and eleven signals were searched on TBSS. We found a total of 14 signals finally, some of the signals, including bullous eruption, arthrosis, renal pain, leg pain, were not labeled in South Korea, the United States, and Japan.

Conclusions: We detected 4 unexpected signals associated with the zoster vaccine by signal detection. Since the zoster vaccine had been introduced in South Korea in 2012, the reported data could not be enough, so subsequent studies can be considered after collecting accumulated data. These results suggested potential study directions such as label expansion and identification of causality in adverse events associated with zoster vaccination.