Fig. 2: Antibody/neutralization levels after booster vaccination and special patient cases.

A Anti-RBD antibody levels between patients received 2 vaccine doses (cyan, n = 29) versus patients received >2 vaccine doses (magenta, n = 11) at 4–6 months following completion of initial vaccination series (2 doses). B Neutralizing antibody levels between patients received 2 vaccine doses (cyan, n = 34) versus patients received >2 vaccine doses (magenta, n = 6) at 4–6 months following completion of initial vaccination series (2 doses). C Neutralizing antibody levels in patients with low neutralization in relation to time and administration of vaccination doses (D1: 1st dose, D2: 2nd dose, D3: 3rd dose and D4: 4th dose). D Anti-RBD antibody levels in patients who contracted SARS-CoV-2 in relation to vaccination doses and SARS-CoV-2 infection (shown as red line labelled C19). E Neutralizing antibody levels in patients who contracted SARS-CoV-2 in relation to vaccination doses and SARS-CoV-2 infection (shown as red line labelled C19). A, B Mann–Whitney test used for comparison between groups. (****p < 0.0001; **p < 0.01;).