Center of Excellence in Clinical Virology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
Osteoarthritis and Musculoskeleton Research Unit, Faculty of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand.
J Infect Dis. 2022 Oct 17;226(8):1372-1381. doi: 10.1093/infdis/jiac092.
The use of an inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine (CoronaVac) against SARS-CoV-2 is implemented worldwide. However, waning immunity and breakthrough infections have been observed. Therefore, we hypothesized that the heterologous booster might improve the protection against the delta and omicron variants.
A total of 224 individuals who completed the 2-dose CoronaVac for 6 months were included. We studied reactogenicity and immunogenicity after a heterologous booster with the inactivated vaccine (BBIBP), the viral vector vaccine (AZD1222), and the messenger ribonucleic acid (mRNA) vaccine (both BNT162B2 and mRNA-1273). We also determined immunogenicity at 3- and 6-month boosting intervals.
The solicited adverse events were mild to moderate and well tolerated. Total receptor binding domain (RBD) immunoglobulin (Ig), anti-RBD IgG, focus reduction neutralization test (FRNT50) against delta and omicron variants, and T-cell response were highest in the mRNA-1273 group followed by the BNT162b2, AZD1222, and BBIBP groups, respectively. We also witnessed a higher total Ig anti-RBD in the long-interval than in the short-interval group.
All 4 booster vaccines significantly increased binding and neutralizing antibodies in individuals immunized with 2 doses of CoronaVac. The present evidence may benefit vaccine strategies to thwart variants of concern, including the omicron variant.
全球范围内使用灭活的严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）疫苗（科兴疫苗）来预防 SARS-CoV-2。然而，人们已经观察到免疫效力下降和突破性感染的情况。因此，我们假设异源加强免疫可能会提高对 delta 和 omicron 变异株的保护效果。
共纳入了 224 名完成 2 剂科兴疫苗接种 6 个月的个体。我们研究了使用灭活疫苗（BBIBP）、病毒载体疫苗（AZD1222）和信使核糖核酸（mRNA）疫苗（均为 BNT162B2 和 mRNA-1273）进行异源加强免疫后的不良反应和免疫原性。我们还确定了在 3 个月和 6 个月加强免疫间隔的免疫原性。
不良事件是轻度到中度的，并且耐受性良好。总受体结合域（RBD）免疫球蛋白（Ig）、抗 RBD IgG、针对 delta 和 omicron 变异株的焦点减少中和试验（FRNT50）和 T 细胞反应在 mRNA-1273 组最高，其次是 BNT162b2、AZD1222 和 BBIBP 组。我们还观察到长间隔组的总 Ig 抗 RBD 高于短间隔组。
所有 4 种加强疫苗在接种 2 剂科兴疫苗的个体中均显著提高了结合抗体和中和抗体。现有证据可能有利于疫苗策略，以阻止包括 omicron 变异株在内的关注变异株的传播。
