Convalescent plasma (CP) have been used for treatment of COVID-19, but their effectiveness varies significantly . Moreover, the impact of CP treatment on the composition of SARS-CoV-2 antibodies in COVID-19 patients and antibody markers that differentiate between those who survive and those who succumb to the COVID-19 disease are not well understood . Herein, we performed longitudinal analysis of antibody profile on 115 sequential plasma samples from 16 hospitalized COVID-19 patients treated with either CP or standard of care, only half of them survived . Differential antibody kinetics was observed for antibody binding, IgM/IgG/IgA distribution, and affinity maturation in 'survived' vs. 'fatal' COVID-19 patients . Surprisingly, CP treatment did not predict survival . Strikingly, marked decline in neutralization titers was observed in the fatal patients prior to death, and convalescent plasma treatment did not reverse this trend . Furthermore, irrespective of CP treatment, higher antibody affinity to the SARS-CoV-2 prefusion spike was associated with survival outcome, while sustained elevated IgA response was associated with fatal outcome in these COVID-19 patients . These findings propose that treatment of COVID-19 patients with convalescent plasma should be carefully targeted, and effectiveness of treatment may depend on the clinical and immunological status of COVID-19 patients as well as the quality of the antibodies in the convalescent plasma.