Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Japan.
Division of Cardiovascular Medicine, Hyogo Prefectural Kakogawa Medical Center, Kakogawa, Japan.
Front Immunol. 2022 Feb 24;13:773652. doi: 10.3389/fimmu.2022.773652. eCollection 2022.
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the virus responsible for the Coronavirus Disease 2019 (COVID-19) pandemic. The emergence of variants of concern (VOCs) has become one of the most pressing issues in public health. To control VOCs, it is important to know which COVID-19 convalescent sera have cross-neutralizing activity against VOCs and how long the sera maintain this protective activity.
Sera of patients infected with SARS-CoV-2 from March 2020 to January 2021 and admitted to Hyogo Prefectural Kakogawa Medical Center were selected. Blood was drawn from patients at 1-3, 3-6, and 6-8 months post onset. Then, a virus neutralization assay against SARS-CoV-2 variants (D614G mutation as conventional strain; B.1.1.7, P.1, and B.1.351 as VOCs) was performed using authentic viruses.
We assessed 97 sera from 42 patients. Sera from 28 patients showed neutralizing activity that was sustained for 3-8 months post onset. The neutralizing antibody titer against D614G significantly decreased in sera of 6-8 months post onset compared to those of 1-3 months post onset. However, the neutralizing antibody titers against the three VOCs were not significantly different among 1-3, 3-6, and 6-8 months post onset.
Our results indicate that neutralizing antibodies that recognize the common epitope for several variants may be maintained for a long time, while neutralizing antibodies having specific epitopes for a variant, produced in large quantities immediately after infection, may decrease quite rapidly.
严重急性呼吸系统综合症冠状病毒 2 型（SARS-CoV-2）是引发 2019 年冠状病毒病（COVID-19）大流行的病毒。关注变异株（VOC）的出现已成为公共卫生领域最紧迫的问题之一。为了控制 VOC，了解 COVID-19 恢复期血清对 VOC 具有交叉中和活性以及血清能维持这种保护活性的时间长短非常重要。
选择 2020 年 3 月至 2021 年 1 月期间在兵库县加古川医疗中心因感染 SARS-CoV-2 而住院的患者的血清。在发病后 1-3、3-6 和 6-8 个月时从患者身上抽取血液。然后，使用真病毒对 SARS-CoV-2 变体（D614G 突变作为常规株；B.1.1.7、P.1 和 B.1.351 作为 VOC）进行病毒中和测定。
我们评估了 42 名患者的 97 份血清。28 名患者的血清在发病后 3-8 个月保持中和活性。与发病后 1-3 个月相比，发病后 6-8 个月的血清对 D614G 的中和抗体滴度显著降低。然而，发病后 1-3、3-6 和 6-8 个月的血清对三种 VOC 的中和抗体滴度没有显著差异。
我们的结果表明，识别几个变体共有表位的中和抗体可能会长期维持，而针对变体特定表位的中和抗体在感染后立即大量产生，可能会迅速下降。
