Preparation of Equine Immunoglobulin against Smallpox and Evaluation of its Immunoprotective Effect

Announcing a new article publication for Zoonoses journal.  Smallpox, a severe infectious disease caused by the smallpox virus, causes a death rate as high as 30% within 15-20 days after infection. Therefore, development of anti-Smallpox product as a strategic reserve is urgently needed.

Pepsin-digested F(ab′)2 fragments of serum IgG from horses was prepared and tested. Transmission electron microscopy indicated that the purified virus showed morphology consistent with VVTT. The titer was above 1.0 × 107 PFU/mL. The purity of the antigen exceeded 90%, according to HPLC. After purification and cleavage, the yield of the purified product F(ab′)2 was approximately 1.3%, its purity exceeded 90%, and the neutralizing antibody titer exceeded 1:3200. F(ab′)2 fragments had good preventive and therapeutic effects in mice at antibody doses of 5.2 mg/mL and 2.6 mg/mL. The viral loads of the drug-treated mice were suppressed to varying degrees, and the higher dose groups (5.2 and 2.6 mg/mL) showed a 2-3 fold lower viral load than that in the control group.

A process for producing equine immunoglobulin F(ab′)2 against VVTT was established. The prepared horse anti-smallpox immunoglobulin product had good neutralizing antibody effects on VVTT. The highly purified preparation may serve as a potential candidate for smallpox treatment.

Zoonoses is fully open access journal for research scientists, physicians, veterinarians, and public health professionals working on diverse disciplinaries of zoonotic diseases.

Zoonoses is now open for submissions; articles can be submitted online at

Please visit to learn more about the journal.

Editorial Board:

Zoonoses is available on ScienceOpen (

Submissions may be made using ScholarOne (

There are no author submission or article processing fees.

Follow Zoonoses on Twitter @ZoonosesJ; Facebook ( ) and LinkedIn (

eISSN 2737-7474

ISSN 2737-7466

Article reference: Bochang Shi, Hui Han and Lingyun Tan et al. Preparation of Equine Immunoglobulin F(ab′)2 against Smallpox and Evaluation of its Immunoprotective Effect. Zoonoses. Vol. 3(1). DOI: 10.15212/ZOONOSES-2022-0048

Updated: February 13, 2023 — 5:23 pm