Broad-spectrum of non-serious adverse events following COVID-19 vaccination: A population-based cohort study in Seoul, South Korea

Abstract

ObjectiveTo examine the incidence rate and risk of non-fatal irAEs, including gynecological, hematological, dermatological, ophthalmological, otologic, and dental problems following the COVID-19 vaccination.MethodsWe conducted a population-based cohort study from the National Health Insurance Service (NHIS) database in Seoul, South Korea. The non-fatal irAEs included gynecological, hematological, dermatological, ophthalmological, ear, and periodontal problems as reported by the Vaccine Adverse Event Reporting Center. The cumulative incidence rate per 10,000 population, Odds ratio, and Hazard ratio (HR) with 95% Confidence Interval (CI) were measured to assess the non-fatal irAEs after COVID-19 vaccination.ResultsThe cIR of non-fatal irAEs for three months was significantly higher in vaccinated subjects than in non-vaccinated subjects, except for endometriosis. The vaccination significantly increased the risks of all the non-fatal irAEs except for visual impairment. The risk of inner ear disease showed the highest HRs (HR [95% CI] = 2.368 [2.153-2.604]) among the non-fatal irAEs following COVID-19 vaccination. Among the vaccinated subjects, heterologous vaccination was associated with the increased risk of most of the non-fatal irAEs.ConclusionsThe three-month risks of incidental non-fatal irAEs are substantially higher in the COVID-19 vaccinated subjects than in non-vaccinated controls. Our findings suggested that vaccinated subjects with predisposition are potentially vulnerable to the occurrence of diverse irAEs although the COVID-19 vaccines may not be fatal.