Monoclonal Antibodies Combined with Adenovirus-Vectored Interferon Significantly Extend the Treatment Window in Ebola Virus-

Monoclonal antibodies (MAbs) are currently a promising treatment strategy against Ebola virus infection. This study combined MAbs with an adenovirus-vectored interferon (DEF201) to evaluate the efficacy in guinea pigs and extend the treatment window obtained withMAbs alone. Initiating the combination therapy at 3 days postinfection (d.p.i.) provided 100 % survival, a signifi-cant improvement over survival with either treatment alone. The administration of DEF201 within 2 d.p.i. permits later MAb use, with protective efficacy observed up to 8 d.p.i. Ebola virus is one of the most virulent human pathogens, andinfection with the Zaire ebolavirus (EBOV) species results in up to 90%mortality (1). Ebola outbreaks aremostly concentrated in remote areas of sub-Saharan Africa (2), but evidence of prior Ebola infection of swine in the Philippines (3), the presence of Ebola virus antibodies among orangutans in Indonesia (4) and bats in China (5), and the existence of an Ebola virus-like filovirus among European insectivorous bats (6) indicates that Ebola virus may bemore widespread than previously thought. Since pigs have been established as a new intermediate host for Ebola (3), with effective transmission to nonhuman primates (NHPs) (7), there i