Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, China.
Front Immunol. 2022 Sep 20;13:990071. doi: 10.3389/fimmu.2022.990071. eCollection 2022.
Although immune response enhancement has been reported after primary and booster vaccines of CoronaVac, neutralization breadth of SARS-CoV-2 variants is still unclear. In the present study, we examined the neutralization magnitude and breadth of SARS-CoV-2 variants including Beta (B.1.351), Delta (B.1.617.2) and Omicron (B.1.1.529) in 33 convalescent COVID-19 patients and a cohort of 55 medical staff receiving primary CoronaVac vaccines and an additional homologous booster dose. Results showed that, as compared with the two-dose primary vaccination, the homologous booster dose achieved 2.24-, 3.98-, 4.58- and 2.90-fold increase in neutralization titer against wild-type, Beta, Delta, and Omicron, respectively. After booster dose, neutralization titer reduction for variants was less than that after the primary vaccine or that for convalescents. The proportion of recipients able to neutralize 2 or more variants increased from 36.36% post the primary vaccination to 87.27% after the booster. Significant increase in neutralization breadth of 1.24 (95% confidence interval (CI), 0.89-1.59) variants was associated with a log increase in neutralization titer against the wild-type. In addition, anti-RBD IgG level was identified as an excellent surrogate for positive neutralization of SARS-CoV-2 and neutralization breadth of variants. These findings highlight the value of an additional homologous CoronaVac dose in broadening the cross-neutralization against SARS-CoV-2 variants, and are critical for informing the booster dose vaccination efforts.
虽然科兴疫苗的基础免疫和加强免疫均可增强免疫应答，但对 SARS-CoV-2 变异株的中和广度仍不清楚。本研究中，我们检测了 33 名新冠康复患者和 55 名接种科兴疫苗基础免疫和同源加强免疫的医务人员对包括 Beta（B.1.351）、Delta（B.1.617.2）和 Omicron（B.1.1.529）在内的 SARS-CoV-2 变异株的中和抗体效价和广度。结果显示，与两剂基础免疫相比，同源加强免疫使针对野生型、Beta、Delta 和 Omicron 的中和抗体效价分别提高了 2.24 倍、3.98 倍、4.58 倍和 2.90 倍。加强免疫后，变异株的中和抗体效价下降幅度小于基础免疫后或康复患者的下降幅度。能中和 2 种或以上变异株的受种者比例从基础免疫后的 36.36%增加到加强免疫后的 87.27%。中和野生型病毒的抗体效价对数增加与对 1.24 种（95%置信区间（CI），0.89-1.59）变异株的中和广度显著增加相关。此外，抗 RBD IgG 水平可作为 SARS-CoV-2 中和阳性和变异株中和广度的良好替代指标。这些发现强调了额外接种同源科兴疫苗对扩大对 SARS-CoV-2 变异株的交叉中和作用的价值，这对加强免疫接种工作具有重要意义。
