Equine-Origin Immunoglobulin Fragments Protect Nonhuman Primates from Ebola Virus Disease

EBOV is one of the deadliest viruses to humans. It has been over 40 years since EBOV was first reported, but no cure is available. Research breakthroughs over the past 5 years have shown that MAbs constitute an effective therapy for EBOV infections. However, MAbs are expensive and difficult to produce in large amounts and therefore may only play a limited role during an epidemic. A cheaper alternative is required, especially since EBOV is endemic in several third world countries with limited medical resources. Here, we used a standard protocol to produce large amounts of antiserum F(ab′) 2 fragments from horses vaccinated with an EBOV vaccine, and we tested the protectiveness in monkeys. We showed that F(ab′) 2 was effective in 100% of monkeys even after the animals were visibly ill with EBOV disease. Thus, F(ab′) 2 could be a very good option for large-scale treatments of patients and should be advanced to clinical testing.