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.
Keywords: COVID-19; IgA; IgG; coronaviral infection; humoral immune response.
Copyright © 2022 Miyara, Saichi, Sterlin, Anna, Marot, Mathian, Atif, Quentric, Mohr, Claër, Parizot, Dorgham, Yssel, Fadlallah, Chazal, Haroche, Luyt, Mayaux, Beurton, Benameur, Boutolleau, Burrel, de Alba, Mudumba, Hockett, Gunn, Charneau, Calvez, Marcelin, Combes, Demoule, Amoura and Gorochov.