1. From Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald (A.G., T.T.), and the Division of Safety of Medicinal Products and Medical Devices, Paul-Ehrlich-Institut (Federal Institute for Vaccines and Biomedicines), Langen (K.W.) — both in Germany; the Departments of Pathology and Molecular Medicine and of Medicine, McMaster University, Hamilton, ON, Canada (T.E.W.); and the Department of Medicine I, Division of Hematology and Hemostaseology, Medical University of...