No significant increase in autoimmune, autoinflammatory risks with mRNA COVID-19 vaccine
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Key takeaways:
- The mRNA-based COVID-19 vaccine did not significantly increase the risk of autoimmune or autoinflammatory diseases.
- Age, sex, type of mRNA-based vaccine and cross-vaccination status did not change risk.
The mRNA-based COVID-19 vaccine does not significantly increase the risk of autoimmune or autoinflammatory diseases, according to data published in the Journal of the American Academy of Dermatology.
“Contrary to some prior studies suggesting a possible link between mRNA-based COVID-19 vaccines and autoimmune responses, this nationwide study yielded no significant increase in autoimmune skin and connective tissue disorders following the vaccinations,” Solam Lee, MD, PhD, of the department of dermatology at Yonsei University Wonju College of Medicine, told Healio. “These findings challenge previous concerns and provide reassurance regarding the safety of these vaccines.”
In a nationwide population-based study conducted in South Korea, participants were selected that received at least one dose of the mRNA COVID-19 vaccination between Sept. 8, 2020, and Dec. 31, 2021. The researchers matched historical pre-pandemic controls for age and sex in a 1:1 ratio to compare the incidence rate and risk of disease outcomes between the vaccination and historical cohorts.
Of the 7,672,924 individuals who were vaccinated with at least one dose of the mRNA-based COVID-19 vaccine, 3,838,120 were assigned to the vaccination cohort and 3,834,804 were assigned to the historical cohort.
The researchers found that participants in the vaccinated cohort vs. historical cohort did not show any significantly increased risk of alopecia areata (adjusted HR = 0.98; 95% CI, 0.92-1.05), alopecia totalis (aHR = 0.89; 95% CI, 0.69-1.14), psoriasis (aHR = 0.89; 95% CI, 0.81-0.97), vitiligo (aHR = 0.96; 95% CI, 0.84-1.11), ulcerative colitis (HR = 0.88; 95% CI, 0.72-1.07), rheumatoid arthritis (aHR = 0.92; 95% CI 0.87-0.98), systemic sclerosis (aHR = 0.82; 95% CI, 0.46-1.45) and Sjogren syndrome (aHR = 0.90; 95% CI, 0.74-1.1), in addition to other autoimmune and autoinflammatory diseases.
However, the researchers did find a considerably increased risk of myocarditis (aHR = 76.48; 95% CI, 18.67-313.39), pericarditis (aHR = 6.24; 95% CI, 3.8-10.24) and thrombocytopenia (aHR = 1.45; 95% CI, 1.31-1.61) in the vaccination cohort compared with the historical cohort.
The type of mRNA vaccine, age and cross-vaccination status were not independently associated with increased risk of disease outcomes. Only ANCA-associated vasculitis was associated with an increased risk in vaccinated female participants (aHR = 5.09; 95% CI, 1.09-23.68), although the researchers cautioned this finding “requires careful interpretation” since the number of events was very small.
“For everyday clinicians, these results provide reassurance about the safety of mRNA-based COVID-19 vaccines,” Lee told Healio. “They can confidently continue to administer these vaccines, knowing they do not significantly increase the risk of a wide range of autoimmune connective tissue disorders.”