In response

Affiliations

• ¹ American Red Cross, Biomedical Services Headquarters, Washington, District of Columbia, USA.
• ² Department of Pathology, Johns Hopkins University, Baltimore, Maryland, USA.
• ³ American Red Cross, Scientific Affairs, Gaithersburg, Maryland, USA.
• ⁴ Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.