Real-world safety outcomes of COVID-19 mRNA vaccine: A result from Korea post-marketing surveillance

The COVID-19 pandemic has caused a substantial global health burden, highlighting the need for post-authorization safety evaluation in real-world settings. BNT162b2 is a widely used mRNA COVID-19 vaccine, and, in addition to the original strain-based formulation, BA.1-, BA.4/5-, XBB.1.5-, and JN.1-adapted formulations were introduced sequentially. This study aimed to evaluate the real-world safety profile of the BNT162b2 product family using post-marketing surveillance data collected in Korea. Data collection was conducted from 50 sites. Solicited adverse events (AEs) were collected for 7 days, and unsolicited AEs for 28 days after vaccination. AEs occurring beyond Day 28 were also collected if reported during routine follow-up, without restriction on the collection period. Of 6,343 enrolled participants, 6,251 were included in the safety analysis set. Overall AEs were reported in 1,640 participants (26.2%) and adverse drug reactions (ADRs) in 1,610 participants (25.8%). Serious AEs occurred in 2 participants (<0.1%), and serious ADRs in 1 participant (<0.1%); no unexpected serious ADRs were identified. Solicited AEs were predominantly mild reactogenicity events, most commonly injection site pain, myalgia, fatigue, and headache. The overall safety profile of the BNT162b2 product family was generally manageable in this predominantly adult population, with very few serious ADRs and no unexpected serious ADRs identified. However, due to limited systematic capture of adverse events of special interest (AESIs) and underrepresentation of pediatric participants, AESI-related findings and pediatric safety conclusions should be interpreted with caution. These findings provide complementary real-world evidence regarding the safety of BNT162b2-adapted vaccines in Korea.