The Claim:
A common concern about vaccines, often exploited by anti-vaccine factions, is that they will overstimulate the immune system into developing an autoimmune disorder.
The Facts:
A large study from South Korea and Japan found that people who had COVID are at a higher risk of developing autoimmune rheumatic diseases (AIRD) ,such as rheumatoid arthritis and lupus, within a year after infection. However, COVID-infected patients who had prior vaccination against COVID did not show increased risk for AIRD, with the exception of patients with severe COVID.
The study, one of the largest on this topic in Asian populations, used data from millions of adults and compared those who had COVID-19 with those who had influenza or were not infected. It showed that the risk of autoimmune diseases after COVID was about 25% to 30% higher compared to those without infection. This risk dropped back to normal after a year. Vaccination prior to infection seemed to reduce the risk of developing AIRD by about half.