SARS-CoV-2 infection is associated with increased risk for autoimmune inflammatory rheumatic diseases up to 12 months after infectionas a large study found, published in the journal “Annals of Internal Medicine”.

Researchers from Kyung Hee University, Seoul in South Korea used data from two national large-scale general population studies in Korea and Japan. Specifically, they studied data on more than ten million Korean and twelve million Japanese adults, including those with Covid-19, during the period between January 2020 and December 2021. Patients with Covid-19 were matched with patients with influenza infection and with those who were not infected by the two infections. They then evaluated the data one, six and twelve months after contracting Covid-19 or the flu.

As they found out, those had Covid-19 had an increased risk of autoimmune inflammatory rheumatic diseases up to 12 months after diagnosis compared to the other two groups. Greater severity of infection was associated with a higher risk of incident rheumatic disease.

The authors also found that vaccination against Covid-19 was associated with a reduced risk of autoimmune inflammatory rheumatic diseases, except for those who developed severe Covid-19 despite vaccination.