In Vitro Characterization and In Vivo Effectiveness of Ebola Virus Specific Equine Polyclonal F(ab′)

There is no vaccine or approved therapy against lethal Ebola virus (EBOV). We investigated a proven technology platform to produce polyclonal IgG fragments, F(ab′)₂, against EBOV. Horses immunized with nanoparticles harboring surface glycoprotein trimers of EBOV-Zaire/Makona produced anti-Ebola IgG polyclonal antibodies with high neutralization activity. Highly purified equine anti-Ebola F(ab′)₂ showed strong cross-neutralization of 2 Zaire EBOV strains (Gabon 2001 and Makona) and in vivo 3 or 5 daily F(ab′)₂ intraperitoneal injections provided 100% protection to BALB/c mice against lethal EBOV challenge. Rapid preparation of purified equine anti-Ebola F(ab′)₂ offers a potentially efficient therapeutic approach against EBOV disease in humans.