Data on the association between the development of autoimmune diseases and coronavirus disease 2019 (COVID-19) vaccination are limited.
To investigate the incidence and risk of autoimmune connective tissue disorders following mRNA-based COVID-19 vaccination.
This nationwide population-based study was conducted in South Korea. Individuals who received vaccination between September 8, 2020–December 31, 2021, were identified. Historical pre-pandemic controls were matched for age and sex in 1:1 ratio. The incidence rate and risk of disease outcomes were compared.
A total of 3,838,120 vaccinated individuals and 3,834,804 controls without evidence of COVID-19 were included. The risk of alopecia areata, alopecia totalis, primary cicatricial alopecia, psoriasis, vitiligo, anti-neutrophil cytoplasmic antibody-associated vasculitis, sarcoidosis, Behcet disease, Crohn disease, ulcerative colitis, rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, Sjogren syndrome, ankylosing spondylitis, dermato/polymyositis, and bullous pemphigoid was not significantly higher in vaccinated individuals than in controls. The risk was comparable according to age, sex, type of mRNA-based vaccine, and cross-vaccination status.
The risk of autoimmune connective tissue diseases after mRNA-based COVID-19 vaccination is not well elucidated.This nationwide study found that most autoimmune connective tissue diseases were not significantly increased after mRNA-based COVID-19 vaccination. However, limited statistical power prevented detection of potential risks for some rare outcomes. Nevertheless, results suggest any existing risk is not large. These findings could aid in the evaluation and management of autoimmune manifestations following vaccination for COVID-19.