The newly emerged severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has infected millions of people and caused tremendous morbidity and mortality worldwide.Effective treatment for coronavirus disease 2019(COVID-19)due to SARS-CoV-2 infection is lacking,and different therapeutic strategies are under testing.Host humoral and cellular immunity to SARS-CoV-2 infection is a critical determinant for patients'outcomes.SARS-CoV-2 infection results in seroconversion and production of anti-SARS-CoV-2 antibodies.The antibodies may suppress viral replication through neutralization but might also participate in COVID-19 pathogenesis through a process termed antibody-dependent enhancement.Rapid progress has been made in the research of antibody response and therapy in COVID-19 patients,including characterization of the clinical features of antibody responses in different populations infected by SARS-CoV-2,treatment of COVID-19 patients with convalescent plasma and intravenous immunoglobin products,isolation and characterization of a large panel of monoclonal neutralizing antibodies and early clinical testing,as well as clinical results from several COVID-19 vaccine candidates.In this review,we summarize the recent progress and discuss the implications of these findings in vaccine development.