[The Comparison of Coronavirus Disease 2019 Vaccine Adverse Events between Korea and the UK and Implications for Vaccine Adverse Event Management System].

Coronavirus disease 2019 (COVID-19) vaccination programs in the Republic of Korea (ROK) and the United Kingdom (UK) have been successfully implemented by providing the most available vaccines in a timely manner. Both countries have collected post-vaccination adverse event (AE) data to continuously monitor evolving vaccine safety, and the cumulative number of individual case safety reports (ICSRs) obtained in the two countries has exceeded 0.48 million in total, respectively. The numbers of AEs per ICSR and AE types as well as the probability of having a serious AE per ICSR were lower in the ROK than in the UK. These findings could imply that the ROK might have adopted different standards and processes from those in the UK. For example, there were marked inter-country differences in acceptable reporter types, seriousness criteria, causality assessment criteria, and AE coding system, which could have resulted from the low level of acceptance of internationally recognized pharmacovigilance principles in the ROK. The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines are widely adopted by national regulatory authorities in many countries including the United States, European Union countries, and the UK, with research institutions and pharmaceutical companies being no exception. The ROK needs to improve the Adverse Event Following Immunization management system to practice more effective and sustainable vaccine safety monitoring by adopting ICH guidelines.