Challenge Transfusion of INTERCEPT Pathogen Reduced Red Blood Cells (RBCs) in Subjects With or Without Pre-existing Antibodies to INTERCEPT RBCs

Inclusion Criteria: * Age ≥4 years in children who meet the requirement of US Code of Federal Regulation (CFR) Title 21, §50.53 as determined by the local Institutional Review Board (IRB). * Control subjects shall have no current or previously documented antibodies to INTERCEPT RBC. * Test subjects shall have current or previously documented natural or treatment-emergent antibodies to INTERCEPT RBCs. * History of prior transfusion with allogeneic blood products (INTERCEPT or non-INTERCEPT treated). * \>120 days from the subjects most recent exposure to Study RBCs (pathogen reduced or non-pathogen reduced - if any) prior to the planned study transfusion. * Signed and dated informed consent form Exclusion Criteria: * Foreseeable active blood loss due to trauma, surgery, or pathologic condition during the study period. * Exposure to another interventional drug or device in a clinical study within 28 days prior to enrollment or concurrently during the study. * Positive Direct Antiglobulin Test (≥2+) at the time of screening, prior to the first study transfusion. * Current or historical medical conditions judged by the Investigator to significantly increase the risk of morbidity/mortality due to hemolysis or the medical management of acute hemolysis. * Treatment with any medication known to affect RBC viability at the time of enrollment (e.g., ribavirin, sulfa drugs, chemotherapy medications, methylene blue, dapsone, levodopa, methyldopa, nitrofurantoin and its derivatives, phe…