United Diagnostic and Research Center for Clinical Genetics, Women and Children's Hospital, School of Medicine and School of Public Health, Xiamen University, Xiamen, Fujian, China.
Department of Clinical Laboratory, Women and Children's Hospital, School of Medicine, Xiamen University, Xiamen, Fujian, China.
Front Immunol. 2023 Feb 3;14:1099629. doi: 10.3389/fimmu.2023.1099629. eCollection 2023.
Coronavirus Disease 2019 (Covid-19) severely impacted the health, society, and economy around the world. With declining protective efficacy of primary vaccination and the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, a Covid-19 booster vaccination is being fully implemented globally. Many people received three doses of BBIBP-CorV inactivated vaccine in China and other developing countries. However, the antibody response and immune persistence of the homologous BBIBP-CorV booster vaccination is yet to be thoroughly evaluated, as previous studies focused within one month after the third dose. In this study, 97 participants were enrolled to analyze the antibody response and immune persistence within 6 months as well as the safety within 7 days after the third-dose of homologous BBIBP-CorV inactivated vaccine. The seroconversion rate for total antibody against the receptor binding domain (RBD) of the SARS-CoV-2 spike (S) protein were both 100% at month 1 and month 6 after the third dose. The IgG against the RBD of the SARS-CoV-2 S protein seroconversion rate increased from 42.27% before the third dose to 100% 1 month after the third dose and then slightly decreased to 98.97% 5 months later. Positive IgM against the RBD of the SARS-CoV-2 S protein was rare and was observed in only one participant at month 1 after the third dose. The neutralizing antibody levels at month 1 and month 6 after the third dose increased 63.32-fold and 13.16-fold compared with those before the third dose, and the positive rate for neutralizing antibody was still 100% at month 6 after the third dose. Importantly, the antibody responses induced by the vaccine and immune persistence were not affected by sex or age. No serious adverse reactions were reported. Total antibody and IgG against the RBD of the SARS-CoV-2 S protein were highly correlated with neutralizing antibody, suggesting that total antibody and IgG against the RBD of the SARS-CoV-2 S protein could be used as predictors for neutralizing antibody. In conclusion, the third dose of homologous BBIBP-CorV inactivated vaccine induced a robust antibody response and moderate immune persistence. These finding are of great significance for development future vaccination strategies.
2019 年冠状病毒病（COVID-19）严重影响了全球的健康、社会和经济。随着初级疫苗保护效力下降和严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）变异株的传播，COVID-19 加强疫苗接种正在全球范围内全面实施。许多人在中国和其他发展中国家接种了三剂 BBIBP-CorV 灭活疫苗。然而，同源性 BBIBP-CorV 加强疫苗接种的抗体反应和免疫持久性尚未得到彻底评估，因为之前的研究集中在第三剂后一个月内。在这项研究中，招募了 97 名参与者，以分析第三剂同源 BBIBP-CorV 灭活疫苗接种后 6 个月内的抗体反应和免疫持久性，以及 7 天内的安全性。第三剂后 1 个月和 6 个月时，针对 SARS-CoV-2 刺突（S）蛋白受体结合域（RBD）的总抗体的血清转化率均为 100%。第三剂后 1 个月时，针对 SARS-CoV-2 S 蛋白 RBD 的 IgG 血清转化率从 42.27%增加到 100%，然后略有下降至 5 个月后的 98.97%。针对 SARS-CoV-2 S 蛋白 RBD 的阳性 IgM 很少见，仅在第三剂后 1 个月的 1 名参与者中观察到。第三剂后 1 个月和 6 个月时的中和抗体水平分别比第三剂前增加了 63.32 倍和 13.16 倍，第三剂后 6 个月时的中和抗体阳性率仍为 100%。重要的是，疫苗诱导的抗体反应和免疫持久性不受性别或年龄的影响。未报告严重不良反应。针对 SARS-CoV-2 S 蛋白 RBD 的总抗体和 IgG 与中和抗体高度相关，表明针对 SARS-CoV-2 S 蛋白 RBD 的总抗体和 IgG 可作为中和抗体的预测指标。总之，同源性 BBIBP-CorV 灭活疫苗的第三剂接种可诱导出强大的抗体反应和适度的免疫持久性。这些发现对未来疫苗接种策略的发展具有重要意义。
