Different composite pattern between booster vaccination and breakthrough infection. (a) Neutralizing antibody titre against Wuhan-1 stain for samples collected at D14 post booster vaccinations and D14 post breakthrough infection. n = 20 in I-I-I, n = 10 in I-I-S, n = 16 in recovered Delta breakthrough patients. (b, c) The portion of neutralizing antibody titre compared to total anti-S + N and anti-RBD antibody at 1M post two-dose vaccination, post booster vaccinations and post breakthrough infection. n = 20 in I-I, n = 13 in I-I-I, n = 23 in I-I-S, n = 11 in Delta-Recovery. (d, e) The portion of neutralizing antibodies represented by monoclonal antibody 13G2 or 08B3 compared to total neutralizing antibody for vaccination samples and breakthrough infection samples. n = 13 in I-I-I, n = 23 in I-I-S, n = 11 in Delta-Recovery. ns, not significant; *P < 0.05, ***P < 0.001, ****P < 0.0001.