The objectives of the Recipient Epidemiology and Donor Evaluation Study-IV-Pediatric (REDS-IV-P) program is to evaluate and improve the safety and availability of the blood supply, as well as the safety and effectiveness of transfusion therapies, with attention to not only adults, but also neonates and children who need transfusion. REDS-IV-P is a seven-year multicenter program, in the US and in Brazil, charged with conducting epidemiologic and laboratory studies in blood donors and transfusion recipients. The REDS-IV-P Program is comprised of 4 domestic hubs and a Brazil transfusion program involving investigators from the U.S. and from the Brazilian blood centers. Each domestic hub has a blood center and transfusion services that serve several specialty care and community hospitals participating in REDS-IV-P (total of 22 hospitals). The domestic Hubs and the Brazil international programs are each supported by a Data Coordinating Center (DCC) and Center for Transfusion Laboratory Studies (CTLS). REDS-IV-P is divided into 3 phases: 1) Phase 1 (Years 1-2) includes development of the REDS-IV-P research protocols, the development and pilot of a linked donation-component-recipient (vein to vein) database, the conduct of phase 1 research studies, and the conduct of data analyses using existing transfusion databases; 2) Phase 2 (Years 3-5) includes the conduct of phase 2 research protocols, compilation of the vein to vein database and data analyses, and dissemination of findings through presentations and publications; and 3) Phase 3 (Years 6-7) includes dissemination of findings through presentations and publications, closure of databases, and provision of all deliverables to NHLBI. This contract is for the DCC phase 2 activities.