Recently, Zhongnan Hospital of Wuhan University used YHLO reagents to further analyze the protective immunity of SARS-CoV-2, which provided a basis for understanding the pathogenesis of COVID-19 and provided assistance for the development of effective SARS-CoV-2 vaccine. The research has now been published in the journal Signal Transduction and Targeted Therapy (Impact Factor: 18.187)

A total of 212 samples from 171 COVID-19 convalescent individuals, with a median age of 52 years were enrolled in the study, and 212 blood samples were collected in three time periods (4-6 months, 7-8 months and 9-11 months after diagnosis). At the same time, 30 healthy volunteers were recruited to collect blood samples.

Using serum from patients and healthy donors, IgA, IgM and IgG antibodies against SARS-CoV-2 NP, S1, RBD and NP-S1 antigens were detected. Compared with healthy donors, in follow-up patients, anti-SARS-CoV-2 IgG antibodies are also pronounced than IgA and IgM antibodies until at least 11 months after onset.

Among the patients who were followed up for 4-6 months after the onset, 67.3% (37/55) of the patients were NAb-positive, while 94.4% (67/71) and 71.4% (60/84) of patients had positive NAb within 7–8 months and 9–11 months after the diagnosis, respectively. As expected, NAb was significantly associated with anti-S1 IgG and anti-RBD IgG, but not with anti-NP IgG, indicating that anti-S1 IgG and anti-RBD IgG may be predictors of serum neutralization ability in COVID-19 patients. These findings indicate that most individuals in the recovery phase of COVID-19 have serum that neutralizes SARS-CoV-2 for at least 11 months after the onset of disease.

This study used chemiluminescence SARS-CoV-2 NAb kits produced by Shenzhen YHLO Biotech Co., Ltd were used for the evaluation of NAbs in patients recovering from COVID-19 or the auxiliary evaluation of the effect of the SARS-CoV-2 vaccine. The iFlash-SARS-CoV-2 IgA/IgG/IgM assay was used for qualitative determination of the IgG antibody to SARS-CoV-2 in human serum or plasma using the iFlash immunoassay system. The iFlash-SARS-CoV-2 IgA/IgG/IgM aids in the diagnosis of SARS-CoV-2 infection and the determination of immunity.

Original publication:

Pan Y, Jiang X, Yang L, et al. SARS-CoV-2-specific immune response in COVID-19 convalescent individuals[J]. Signal Transduction and Targeted Therapy, 2021, 6(1): 1-10.

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