Department of Medical Microbiology, Karadeniz Technical University Faculty of Medicine, Trabzon, Turkey.
Department of Medical Microbiology, Bezmialem Vakıf University Faculty of Medicine, Istanbul, Turkey.
Curr Microbiol. 2023 Apr 1;80(5):162. doi: 10.1007/s00284-023-03248-6.
One of the immune responses desired to be achieved by SARS-CoV-2 vaccination is to create neutralizing antibodies (nAbs), thus preventing the development and spread of infection. The aim of this study was to investigate the seropositivity rate, anti-spike antibody levels, and neutralizing capacity of these antibodies against wild type (WT) and alpha variants in serum samples of individuals who had been naturally infected or vaccinated with CoronaVac®. Total anti-spike antibody levels were determined in all samples. Neutralization assays were performed by the reduction of the cytopathic effect in Vero-E6 cells with infectious WT and alpha SARS-CoV-2 variants. Although both naturally infected and vaccinated individuals were all seropositive for antispike antibodies, 84.8% of the vaccinated group, and 89.3% of the naturally infected group had detectable nAbs. The nAbs titers were significantly higher in the naturally infected group for both WT and alfa variant of the virus as compared to the vaccinated individuals. In this study, it was observed that all individuals became seropositive six weeks after exposure to the vaccine or the virus. Moreover, naturally infected individuals had higher levels of nAbs than those vaccinated. The presence of nAbs against the alpha variant in both naturally infected and vaccinated individuals suggests that these antibodies may also be protective against infections, which may be caused by other variants, such as delta and omicron.
接种 SARS-CoV-2 疫苗所期望产生的免疫反应之一是产生中和抗体（nAbs），从而防止感染的发生和传播。本研究旨在调查自然感染或接种科兴疫苗的个体血清样本中针对野生型（WT）和 alpha 变异株的血清阳性率、抗刺突抗体水平和这些抗体的中和能力。所有样本均测定了总抗刺突抗体水平。通过用具有传染性的 WT 和 alpha SARS-CoV-2 变异株降低 Vero-E6 细胞的细胞病变效应来进行中和测定。尽管自然感染和接种疫苗的个体均对抗刺突抗体呈血清阳性，但接种组中有 84.8%，自然感染组中有 89.3%的个体可检测到 nAbs。与接种个体相比，自然感染组针对 WT 和 alfa 变异株的 nAbs 滴度明显更高。在这项研究中，观察到所有个体在接触疫苗或病毒六周后均呈血清阳性。此外，自然感染个体的 nAbs 水平高于接种个体。自然感染和接种个体中均存在针对 alpha 变异株的 nAbs 表明，这些抗体也可能对其他变异株（如 delta 和 omicron）引起的感染具有保护作用。
