ALB and diabetes mellitus: Multivariable regression analysis showed that, in COVID-19-naïve hemodialysis patients, heterologous vaccination and anti-HBs antibodies before SARS-CoV-2 vaccination were independent predictors of SARS-CoV-2-spike-IgG-levels 6 weeks after second vaccination (Table 3), whereas previously identified modifiers including age, sex, Charlson-Comorbidity-Index, diabetes, dialysis vintage, and serum albumin-levels, were not.