The capacity of pre-existing immunity to human common coronaviruses (HCoV) to cross-protect against de novo COVID-19is yet unknown. In this work, we studied the sera of 175 COVID-19 patients, 76 healthy donors and 3 intravenous immunoglobulins (IVIG) batches. We found that most COVID-19 patients developed anti-SARS-CoV-2 IgG antibodies before IgM. Moreover, the capacity of their IgGs to react to beta-HCoV, was present in the early sera of most patients before the appearance of anti-SARS-CoV-2 IgG. This implied that a recall-type antibody response was generated. In comparison, the patients that mounted an anti-SARS-COV2 IgM response, prior to IgG responses had lower titres of anti-beta-HCoV IgG antibodies. This indicated that pre-existing immunity to beta-HCoV was conducive to the generation of memory type responses to SARS-COV-2. Finally, we also found that pre-COVID-19-era sera and IVIG cross-reacted with SARS-CoV-2 antigens without neutralising SARS-CoV-2 infectivity in vitro . Put together, these results indicate that whilst pre-existing immunity to HCoV is responsible for recall-type IgG responses to SARS-CoV-2, it does not lead to cross-protection against COVID-19.
【저자키워드】 COVID-19, IgG, IgA, humoral immune response, coronaviral infection, 【초록키워드】 SARS-CoV-2, IgM, Intravenous immunoglobulin, coronavirus, cross-protection, Antibody Response, in vitro, memory, IgG antibodies, anti-SARS-CoV-2 IgG, sera, response, Patient, SARS-CoV-2 antigen, pre-existing immunity, COVID-19 patients, COVID-19 patient, IgG response, titre, IgM response, de novo, neutralising, healthy donor, responsible, indicated, the patient, anti-SARS-CoV-2 IgG antibody, mounted, 【제목키워드】 SARS-CoV-2, Human, response, Cold, common,