ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India.
ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India; Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India.
Virology. 2021 Jun;558:13-21. doi: 10.1016/j.virol.2021.02.002. Epub 2021 Mar 5.
India is one of the most affected countries by COVID-19 pandemic; but little is understood regarding immune responses to SARS-CoV-2 in this region. Herein we examined SARS-CoV-2 neutralizing antibodies, IgG, IgM, IgA and memory B cells in COVID-19 recovered individual from India. While a vast majority of COVID-19 recovered individuals showed SARS-CoV-2 RBD-specific IgG, IgA and IgM antibodies (38/42, 90.47%; 21/42, 50%; 33/42, 78.57% respectively), only half of them had appreciable neutralizing antibody titers. RBD-specific IgG, but not IgA or IgM titers, correlated with neutralizing antibody titers and RBD-specific memory B cell frequencies. These findings have timely significance for identifying potential donors for plasma therapy using RBD-specific IgG assays as surrogate measurement for neutralizing antibodies in India. Further, this study provides useful information needed for designing large-scale studies towards understanding of inter-individual variation in immune memory to SARS CoV-2 natural infection for future vaccine evaluation and implementation efforts.
印度是受 COVID-19 大流行影响最严重的国家之一，但对该地区针对 SARS-CoV-2 的免疫反应知之甚少。在此，我们检测了来自印度 COVID-19 康复个体的 SARS-CoV-2 中和抗体、IgG、IgM、IgA 和记忆 B 细胞。虽然绝大多数 COVID-19 康复个体均显示出 SARS-CoV-2 RBD 特异性 IgG、IgA 和 IgM 抗体（38/42，90.47%；21/42，50%；33/42，78.57%），但只有一半的个体具有可测的中和抗体滴度。RBD 特异性 IgG 而不是 IgA 或 IgM 滴度与中和抗体滴度和 RBD 特异性记忆 B 细胞频率相关。这些发现对于鉴定使用 RBD 特异性 IgG 检测作为中和抗体替代测量的血浆疗法潜在供体具有及时意义，特别是在印度。此外，该研究还为设计大规模研究提供了有用的信息，以了解 SARS CoV-2 自然感染的个体间免疫记忆的个体差异，从而为未来的疫苗评估和实施工作提供依据。
