Autoimmune conditions following mRNA (BNT162b2) and inactivated (CoronaVac) COVID-19 vaccination: A descriptive cohort study among 1.1 million vaccinated people in Hong Kong. Issue 130 (June 2022)

• Record Type: Journal Article
• Authors: Li, Xue; Gao, Le; Tong, Xinning; Chan, Vivien K.Y.; Chui, Celine S.L.; Lai, Francisco T.T.; Wong, Carlos K.H.; Wan, Eric Y.F.; Chan, Esther W.Y.; Lau, Kui Kai; Lau, Chak Sing; Wong, Ian C.K.
• Is Part Of: Journal of autoimmunity. Issue 130(2022)
• Publication Date: 2022-06
• Subjects: COVID-19 vaccines -- mRNA vaccine -- Inactivated virus vaccine -- Autoimmune diseases -- Pharmacovigilance; Autoimmunity -- Periodicals; Autoimmune diseases -- Periodicals; Autoantibodies -- Periodicals; Autoimmune Diseases -- Periodicals; Auto-immunité -- Périodiques; Maladies auto-immunes -- Périodiques; Electronic journals; 616.978005
• DOI: 10.1016/j.jaut.2022.102830
• Languages: English
• ISSNs: 0896-8411

Abstract

Abstract: Background: Concerns regarding the autoimmune safety of COVID-19 vaccines may negatively impact vaccine uptake. We aimed to describe the incidence of autoimmune conditions following BNT162b2 and CoronaVac vaccination and compare these with age-standardized incidence rates in non-vaccinated individuals. Methods: This is a descriptive cohort study conducted in public healthcare service settings. Territory-wide longitudinal electronic medical records of Hong Kong Hospital Authority users (≥16 years) were linked with COVID-19 vaccination records between February 23, 2021 and June 30, 2021. We classified participants into first/second dose BNT162b2 groups, first/second dose CoronaVac groups and non-vaccinated individuals for incidence comparison. The study outcomes include hospitalized autoimmune diseases (16 types of immune-mediated diseases across six body systems) within 28 days after first and second dose of vaccination. Age-standardized incidence rate ratios (IRRs) with exact 95% confidence intervals (CIs) were estimated using Poisson distribution. Results: This study included around 3.9 million Hong Kong residents, of which 1, 122, 793 received at least one dose of vaccine (BNT162b2: 579, 998; CoronaVac: 542, 795), and 721, 588 completed two doses (BNT162b2: 388, 881; CoronaVac: 332, 707). Within 28 days following vaccination, cumulative incidences for all autoimmune conditions were below 9 per 100, 000 persons, for both vaccines and both doses. None of the age-standardized incidence rates were significantly higher than the non-vaccinated individuals, except for an observed increased incidence of hypersomnia following the first dose of BNT162b2 (standardized IRR: 1.47; 95% CI: 1.10–1.94). Conclusions: Autoimmune conditions requiring hospital care are rare following mRNA and inactivated COVID-19 vaccination with similar incidence to non-vaccinated individuals. The association between first dose BNT162b2 vaccination and immune-related sleeping disorders requires further research. Population-based robust safety surveillance is essential to detect rare and unexpected vaccine safety events. Highlights: Severe autoimmune conditions following mRNA and inactivated virus COVID-19 vaccines are rare. Population-based active surveillance is imperative for vaccine safety monitoring. Long-term autoimmune safety of COVID-19 vaccine warrants further investigation.