Hospitalized adults with COVID-19 in centres in Germany, enrolled in the CAPSID trial (n= 105).
Convalescent plasma (CCP), (n= 53).
Standard care (n= 52).
The primary outcome occurred in 43.4% of patients in the CCP and 32.7% in the control group. The median time to clinical improvement was 26 days in the CCP group and 66 days in the control group. Median time to discharge from hospital was 31 days in the CCP and 51 days in the control group. In the subgroup that received a higher cumulative amount of neutralizing antibodies the primary outcome occurred in 56.0% (vs. 32.1%), with significantly shorter intervals to clinical improvement (20 vs. 66 days), and to hospital discharge (21 vs. 51 days) and better survival (day-60 probability of survival 91.6% vs. 68.1%) compared to the control group.