Roger Y Dodd1,2, Susan L Stramer3, Rachel Smith1,4, Pampee P Young1,4. 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.