目的 研究抗新型冠状病毒（severe acute respiratory syndrome coronavirus 2，SARS-CoV-2）卵黄抗体（egg yolk immunoglobulin，IgY）在体外对SARS-CoV-2及其变异株的中和抑制作用，探讨其作为鼻腔/口腔喷雾剂用于预防和阻断SARS-CoV-2感染的可能性。方法 采用间接ELISA检测抗SARS-CoV-2 IgY原液及成品对刺突（spike，S）蛋白的抗体效价；用微量细胞病变法检测其对SARS-CoV-2的中和活性；用萤光素酶发光法检测其对SARS-CoV-2假病毒的中和作用。结果 抗SARS-CoV-2 IgY原液的抗S抗原效价为1:32 000~1:64 000，成品的效价为1:16 000~1:32 000；两批原液对活病毒的中和效价分别为1:128和1:256，相应的抑制中浓度（median inhibitory concentration，IC₅₀）分别为36.22和36.50 μg/ml；成品对SARS-CoV-2假病毒的IC₅₀均值分别为4.571 μg/ml（WT）和6.07 μg/ml（D614G）；对变异株假病毒的IC₅₀分别为15.09~29.94 μg/ml（B.1.1.7）、41.71~55.56 μg/ml（B.1.351）和16.66~32.33 μg/ml（B.1.617.2）。结论 抗SARS-CoV-2 IgY与SARS-CoV-2重组S蛋白具有良好的结合活性，在体外能显著地中和SARS-CoV-2活病毒、假病毒及变异株假病毒，有望用于SARS-CoV-2感染的预防和阻断。

Objective  To investigate the neutralization and inhibitory effect of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) chicken egg yolk antibodies (IgYs) on SARS-CoV-2 and its variants in vitro, and to explore the possibility of using anti-SARS-CoV-2 IgYs to prevent and block SARS-CoV-2 infection as a nasal or oral spray. Methods  Indirect ELISA was used for detecting the anti-spike (S) titers of anti-SARS-CoV-2 IgYs stock and final product. The neutralization activity of the IgYs on live SARS-CoV-2 was tested by microcytopathic assay. The blocking potency of IgYs on pseudotyped SARS-CoV-2 was evaluated by luciferase luminescence method. Results  The anti-S antigen titers of anti-SARS-CoV-2 IgYs bulk ranged from 1:32 000 to 1:64 000, and that of IgYs final products ranged from 1:16 000 to 1:32 000. The neutralization titers of 2 anti-SARS-CoV-2 IgYs bulks against live virus were 1:128 and 1:256, and the corresponding median inhibitory concentration (IC₅₀) values were 36.22 μg/ml and 36.50 μg/ml, respectively. The mean IC₅₀ values of IgYs final products against pseudotyped SARS-CoV-2 were 4.57 μg/ml (WT) and 6.07 μg/ml (D614G), and the IC₅₀ values for pseudotyped SARS-CoV-2 variants were 15.09-29.94 μg/ml (B.1.1.7), 41.71-55.56 μg/ml (B.1.351) and 16.66-32.33 μg/ml (B.1.617.2), respectively. Conclusions  The anti-SARS-CoV-2 IgYs can effectively bind to SARS-CoV-2 S protien, and show potent inhibitory activity against live SARS-CoV-2, pseudotyped SARS-CoV-2 and its variants infection in vitro. The anti-SARS-CoV-2 IgYs have good potential to be further developed to prevent and control SARS-CoV-2 infection.