Comparison of Waning Immunity Between Booster Vaccination and 2-Dose Vaccination With BNT162b2.

Abstract

S1 specific IgG Ab was measured using an in-house developed ELISA, and the data are presented in IU/ml. The interferon-gamma ELISPOT assay was used to assess the SARS-CoV-2-specific T cell response in isolated PBMCs. T cells were stimulated using SARS-CoV-2 spike-overlapping peptides (Miltenyi Biotec, Bergisch Gladbach, Germany), and the number of spot-forming cells per 5.0×10 5 PBMCs were counted with an automated ELISPOT reader (AID iSPOT; Autoimmun Diagnostika GmbH, Strassberg, Germany). A linear mixed regression model was used to compare the slope from the peak Ab titer to the lowest Ab titer (23 wk after the second vaccination) and the slope from the peak Ab titer