n = 80) from the Amsterdam Cohort Studies on HIV infection and AIDS (ACS) were used to analyze HIV-specific antibody glycosylation. Peripheral blood samples used to purify CMV-specific antibodies ( n = 102) were from same cohort as used for HPA-1a collected by the Finnish Red Cross Blood service, Platelet Immunology Laboratory, Helsinki, Finland and the HIV cohort described above. SARS-CoV-2 patient samples from ICU patients from the Amsterdam UMC COVID study group were included, as well as Sanquin blood donors found seropositive for SARS-CoV-2, and mild longitudinal samples from hospital workers monitored after potential exposure ( 26). A summary of the patients demographics is found in table S1, and detailed patient treatments of the ARDS COVID-19 patients in table S2 (all requiring ventilation). The ACS have been conducted in accordance with the ethical principles set out in the declaration of Helsinki and all participants provided written informed consent. The study was approved by the Academic Medical Center institutional Medical Ethics Committee of the University of Amsterdam.