Abstract
Coronavirus disease 2019 (COVID-19) is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)1,2,3 and individuals with COVID-19 have symptoms that can be asymptomatic, mild, moderate or severe4,5. In the early phase of infection, T- and B-cell counts are substantially decreased6,7; however, IgM8,9,10,11 and IgG12,13,14 are detectable within 14 d after symptom onset. In COVID-19-convalescent individuals, spike-specific neutralizing antibodies are variable3,15,16. No specific drug or vaccine is available for COVID-19 at the time of writing; however, patients benefit from treatment with serum from COVID-19-convalescent individuals17,18. Nevertheless, antibody responses and cross-reactivity with other coronaviruses in COVID-19-convalescent individuals are largely unknown. Here, we show that the majority of COVID-19-convalescent individuals maintained SARS-CoV-2 spike S1- and S2-specific antibodies with neutralizing activity against the SARS-CoV-2 pseudotyped virus, and that some of the antibodies cross-neutralized SARS-CoV, Middle East respiratory syndrome coronavirus or both pseudotyped viruses. Convalescent individuals who experienced severe COVID-19 showed higher neutralizing antibody titres, a faster increase in lymphocyte counts and a higher frequency of CXCR3+ T follicular help (TFH) cells compared with COVID-19-convalescent individuals who experienced non-severe disease. Circulating TFH cells were spike specific and functional, and the frequencies of CXCR3+ TFH cells were positively associated with neutralizing antibody titres in COVID-19-convalescent individuals. No individuals had detectable autoantibodies. These findings provide insights into neutralizing antibody responses in COVID-19-convalescent individuals and facilitate the treatment and vaccine development for SARS-CoV-2 infection.
【초록키워드】 COVID-19, Treatment, neutralizing antibody, Coronavirus disease 2019, Vaccine, Vaccine development, coronavirus, severe COVID-19, antibody, SARS-CoV, SARS-COV-2 infection, Antibody Response, Infection, Symptom, cross-reactivity, Lymphocyte count, serum, Neutralizing activity, Asymptomatic, Pseudotyped virus, autoantibodies, Patient, Mild, Pseudotyped viruses, disease, moderate, Neutralizing antibody response, SARS-CoV-2 spike, B-cell, Frequency, Middle East, symptom onset, acute respiratory syndrome, individual, early phase, help, respiratory syndrome coronavirus, COVID-19-convalescent individuals, neutralizing antibody titres, benefit, Cell, caused, detectable, facilitate, functional, other coronavirus, majority, faster, increase in, COVID-19-convalescent individual, follicular, individuals with COVID-19, neutralizing antibody titre, the antibody, the SARS-CoV-2, 【제목키워드】 circulating, Cell, COVID-19-convalescent individual, cross-neutralizing antibody response, follicular,