#ACR22 Abstr#0769 In patients on DMARDs who didnt seroconvert after primary mRNA COVID vac, is switching to vector or booster with mRNA more effective? An RCT (N=46) showed more pts receiving booster mRNA seroconverted (63%) vs vector (18%). Tcell response was similar @RheumNow https://t.co/5GTsdhNUQZ