Late breaking, but just in time! mRNA COVID-19 3rd dose in RTX pts, w/o Ab response post initial series. After 3rd dose many had ab response or T cell response. Extra vaccine full doses can protect RTX pts from COVID! AbsL17 #ACRbest #ACR21 @RheumNow https://t.co/lIDPzybmT7 https://t.co/jEJ3N6cdjK