The study includes patients of Antoni Jurasz University Hospital No.1 in Bydgoszcz after organ transplantation. To meet the inclusion criteria patients will have to be vaccinated with two doses of the BNT162b2 vaccine. The assessment of the anti-SARS-CoV-2 IgG antibody titer at several time points in each participant. Fresh serum samples were used to measure SARS-CoV-2 IgG on the Siemens Atellica system (Siemens Healthineers, Erlangen, Germany). Results of SARS-CoV-2 IgG were given as U/ml, whereby the cut-off for positivity was defined as ≥1.0 U/ml.
