 This pilot trial will treat subjects in the ECP Group with ECP derived from two donors. ECP will be provided as ECPSDU each comprising 90 - 110mL of plasma from two individual ABO-compatible donors. Two ECPSDU will be administered as immediately sequential infusions. Subjects may receive up to three doses of ECP not less than 48 hours apart. ECP will be provided as Plasma Frozen Within 24 Hours After Phlebotomy PF24 as described in Section 6.1. Pre-treatment and frequent post-treatment blood specimens for assay of anti-EBOV antibody and EBOV viral load by RT-PCR will be obtained from subjects. The pharmacodynamic effect of ECP anti-EBOV, including neutralization titers, on viral load will be examined in the ECP Group. Changes of individual and treatment group clinical and laboratory parameters with time will be described. Between-group and within-group will examine interactions of clinical parameters, outcome, ECP total dose, EBOV viral load, and anti-EBOV IgG ELISAs for Zaire GP residues 1-649 and irradiated Zaire virus, and anti-EBOV PRNT. The MEWS will be assessed as a prognostic tool in the Screened Control Group. Efficacy of ECP will be assessed primarily by comparison of survival to hospital discharge between the ECP Group and the Screened Control Group. 