Fig. 2.

Inhibition of ACE2-trimeric Spike interaction by vaccine-induced antibodies. Serum antibody capacities to block the interaction of ACE2 receptor and Spike protein with the modifications of wild type (wt, Wuhan, n=49) and five VOCs of Alpha (B.1.1.7, n=49), Beta (B.1.351, n=49), Gamma (P.1, n=49), Delta (B.1.617.2, n=48), and Kappa (B.1.617.1, n=48) were analyzed before the vaccination (B1D), one (1wA2D) and 12 (12wA2D) weeks after the second dose. The dotted line indicates the relative OD value of 0·75, which is a threshold for sufficient blocking of ACE2 binding. The box plot comparisons were performed with the Kruskal-Wallis test with Dunn's multiple testing correction; p-values >0·0001 are reported as exact numbers.