Preparation of Equine Immunoglobulin F(ab′)2 against Smallpox and Evaluation of its Immunoprotective Effect

Objective: Smallpox, a severe infectious disease caused by the smallpox virus, causes death rate as high 30% within 15-20 days after infection. Therefore, development of anti-Smallpox product strategic reserve is urgently needed. Methods: We prepared and tested pepsin-digested F(ab′) 2 fragments serum IgG from horses. Results: Transmission electron microscopy indicated that purified virus showed morphology consistent with VVTT. The titer was above 1.0 × 10 7 PFU/mL. purity antigen exceeded 90%, according to HPLC. After purification cleavage, yield approximately 1.3%, its neutralizing antibody 1:3200. had good preventive therapeutic effects in mice at doses 5.2 mg/mL 2.6 mg/mL. viral loads drug-treated were suppressed varying degrees, higher dose groups (5.2 mg/mL) 2-3 fold lower load than control group. Conclusion: A process for producing equine immunoglobulin against VVTT established. horse anti-smallpox on highly preparation may serve potential candidate treatment.