Coronavirus neutralizing antibody titers in IVIG lots (n = 54) against (A) SARS-CoV-2 and (B) HCoV-229E. The IVIG lots were manufactured from plasma either donated by plasmapheresis (S), or recovered from whole blood donations (R), in the United States or central Europe. Each dot represents the mean of 2 independent experiments, except in (B) from 1 EU-R IVIG lot the titer of a single determination is shown. The lines represent the median in each group. Paired t tests were used for determination of significance. Abbreviation: EU, Europe; HCoV, human coronavirus; IVIG, intravenous immunoglobulin; LOD, limit of detection; µNT50, 50% neutralization titer; R, recovered; S, source; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.