Evaluation of immune globulin and recombinant interferon-alpha 2b for treatment of experimental Ebola virus infections

A passive immunization strategy for treating Ebola virus infections was eva luated using BALB/c mice, strain 13 guinea pigs, and cynomolgus monkeys. Gu inea pigs were completely protected by injection of hyperimmune equine IgG when treatment was initiated early but not after viremia had developed. In contrast, mice were incompletely protected even when treatment was initiate d on day 0, the day of virus inoculation. In monkeys treated with one dose of IgG on day 0, onset of illness and viremia was delayed, but all treated animals died. A second dose of IgG on day 5 had no additional beneficial ef fect. Pretreatment of monkeys delayed onset of viremia and delayed death se veral additional days. Interferon-alpha 2b (2 x 10(7) IU/kg/day) had a simi lar effect in monkeys, delaying viremia and death by only several days. Eff ective treatment of Ebola infections may require a combination of drugs tha t inhibit viral replication in monocyte/macrophage-like cells while reversi ng the pathologic effects (e.g., coagulopathy) consequent to this replicati on.