SARS-CoV-2 antibody levels in the two vaccine groups
At enrollment and before receiving the second vaccine booster, the average GMT of anti-RBD IgG in the 191 participants was 61.78, and the GMT of neutralizing antibodies against the BA.4/5 pseudovirus was 31.68. No statistical difference was observed in the baseline antibody levels between the inactivated vaccine group and the Ad5-nCoV group (Antibody responses before and after booster vaccination. ID50 of SARS-CoV-2 RBD-specific IgG antibodies Six months after the fourth vaccination dose, anti-RBD IgG GMTs were significantly higher in the Ad5-nCoV group (344.22; 95% CI, 266.65–444.35) than in the inactivated vaccine group (77.10; 95% CI, 58.24–102.05; Compared with the baseline antibody levels before the fourth vaccination dose, no significant difference in the GMT of anti-RBD IgG was observed at 6 months after the fourth-dose vaccination in the inactivated vaccine group (