ABSTRACT
Background and Aims: Poor glucose control has been associated with increased mortality in COVID-19 patients with type 1 diabetes (T1D). The aim of this study was to assess the effect of glucose control on antibody response to the SARSCoV2 vaccine BNT162b2 in T1D. Method(s): We studied 26 T1D patients scheduled to receive two doses, 21 days apart, of BNT162b2, followed prospectively for six months with regular evaluation of SARS-CoV2 antibodies and glucose control. IgG to spike glycoprotein were assessed by ELISA, and serum neutralization by a live SARS-CoV2 assay (Vero E6 cells system). Continuous glucose monitoring, including time in range (TIR) and above range (TAR), and HbA1c were collected. The primary exposure and outcome measures were prevaccination glucose control, and antibody response after vaccination, respectively. IgG area under the curve (AUC) assessed the overall antibody response along the six-months study timeframe. Result(s): Baseline TIR and TAR strongly correlated with peak- IgG, as well as with the IgG-AUC (TIR: r = 0.75;p = 0.02;TAR: r = -0.81;p = 0.008). Furthermore, pre-vaccination TIR was associated with serum neutralization potency (r = 0.49;P = 0.042). Glucose control along the study timeframe was also associated with IgG response as showed by the correlation between timedependent mean of TIR and TAR and IgG-AUC (TIR: r = 0.93, P < 0.0001;TAR: r = -0.84, P < 0.0001). Pre-vaccination HbA1c was inversely related to peak-IgG, although the relationship did not reach statistical significance (r = -0.33;P = 0.14). Conclusion(s): Our findings indicate a strong relationship between glucose control and antibody response after SARS-CoV2 vaccination, highlighting the importance of achieving wellcontrolled blood glucose for COVID-19 prevention.