Samples from 70 health workers with no previous SARS -CoV2 infection who underwent vaccination (Pfizer-Biontech's BNT162b2) were tested at t0, before the first dose of vaccine; at t1, at the moment of the booster dose, and at t2, 15 days later, to evaluate Ab anti S1-RBD response to the vaccination. In parallel, 210 samples were tested for the Ab anti SARS-CoV-2 concentrations by using the four CLIA automated immunoassays listed in Table 1. The results were expressed in their own original units and in BAU/mL, after recalculation based on the WHO standard NIBSC code 20/136 calibration. The standard alignment coefficients, declared by manufacturers to be perfectly linear, are respectively: LIAISON ® SARS-CoV-2 TrimericS IgG (Dia-Sorin) 1.0 AU/mL=2.6 BAU/mL; Elecsys ® anti-SARS-CoV-2 S (ROCHE) 1.0 U/mL=1.029 BAU/mL; Atellica IM SARS-CoV-2 IgG (sCOVG) (Siemens) 1.0 index=21.8 BAU/mL; MAGLUMI ® SARS-CoV-2 S-RBD IgG (Snibe) 1.0 AU/mL=4.33 BAU/mL.
Passing and Bablok regression as well as the Notched-box-and-Whisker plot were used for comparison between methods (MedCalc Software, ver. 20.014, 2021), using the 140 samples collected at t1 and t2. The study was done in compliance with the World Medical Association Declaration of Helsinki.
Passing and Bablok regression as well as the Notched-box-and-Whisker plot were used for comparison between methods (MedCalc Software, ver. 20.014, 2021), using the 140 samples collected at t1 and t2. The study was done in compliance with the World Medical Association Declaration of Helsinki.