CRP and COVID-19: For the risk factors of severe COVID-19 infection in patients with AAV, patients with severe COVID-19 infection were more likely to be male (OR 1.921 [95% CI 1.020–3.619], P = 0.043), suffer from worse kidney function (Scr, OR 1.901 [95% CI 1.345–2.687], P < 0.001; eGFR, OR 0.976 [95% CI 0.958–0.994], P = 0.009, respectively), and have higher CRP (OR 1.054 [95% CI 1.010–1.101], P = 0.017) and less likely to have initial vaccination (OR 0.469 [95% CI 0.231–0.951], P = 0.036), suggesting that vaccination had a significant protective effect among patients with AAV from severe COVID-19.