Figure 4.

Analysis of RBD binding in sera of heterologous or BNT-vaccinated individuals. IgG binding to the WT-, Delta-, or Omicron-RBD in sera from individuals who received either AZ/BNT/BNT (green) or BNT/BNT/BNT (orange) was analysed by ELISA. Blood samples were each collected at Days 0, 14, and 180 post full immunization and, furthermore, 14 days after a third booster dose. Binding is depicted as OD₄₅₀ values. Turquoise bars indicate the arithmetic mean for each group. Significance is indicated with two stars (**) for a p-value between 0.001 and 0.01, and one star (*) denotes a p-value between 0.01 and 0.05.