In March 2026, Foot-and-Mouth Disease Virus Southern African Territories 1 (FMDV SAT1) was introduced into Xinjiang, Gansu and other regions of China from overseas, drawing nationwide attention. Following the outbreak, China immediately launched the research, development and production of emergency SAT1 vaccines, and approved vaccines manufactured by qualified enterprises for emergency use.
1. Overview of FMDV SAT1
Foot-and-Mouth Disease (FMD), caused by Foot-and-Mouth Disease Virus (FMDV), is an acute, febrile and highly contagious infectious disease, known as the “No.1 Killer” of the animal husbandry industry. As one of the seven major serotypes of FMDV, SAT1 has no cross-immunity with the predominant serotypes circulating in China, namely Serotype O and Serotype A. Its key characteristics are as follows:
1.Extremely high transmissibility: the virus can spread 50 to 100 kilometers via wind.
2.High mortality in young livestock: the mortality rate of young animals exceeds 50%, and that of piglets reaches 80% to 100%.
3.No specific therapeutic drugs are available; vaccination remains the only effective prevention and control measure.
Currently, nationwide emergency vaccination against SAT1 is in full swing. The production capacity and quality of vaccines directly underpin the safety defense line of the animal husbandry sector.
2. Structure of Foot-and-Mouth Disease Virus
FMDV is classified into seven serotypes: Serotype O, Serotype A, Serotype C, SAT1, SAT2, SAT3 and Asia 1. The ongoing outbreak is attributed to SAT1.
FMDV particles measure 23–25 nm in diameter, are non-enveloped and present icosahedral symmetry. The viral capsid consists of four structural proteins: VP1, VP2, VP3 and VP4, featuring a sophisticated yet fragile antigenic structure.
Core objectives of vaccine production:
1.Maximize the structural integrity of viral particles and virus-like particles (VLPs).
2.Efficiently remove heterologous proteins to enhance vaccine purity, safety and immunogenicity.
3.Improve product yield to guarantee large-scale emergency supply.
Separation and purification serve as the most critical procedures determining final vaccine quality.
3. Purification Process Routes
Since there is no effective treatment for FMD, vaccination is the primary prevention approach. On the premise of ensuring vaccine safety, the immunological efficacy of vaccines relies on the integrity of antigens and the diversity of antigenic profiles.
Targeting inactivated FMD vaccines and recombinant FMD vaccines widely researched domestically, Sino Bioengineering leverages its proprietary micro-nano structure control technology, rigid polymer microsphere matrices with excellent pressure resistance and high flow rate tolerance, and has developed dedicated purification process routes for FMD vaccines.
Process 1: Super-pore Anion Exchange Chromatography (for Inactivated Vaccines)
Sino Bioengineering’s super-pore anion exchange chromatography media are rigid resins specially developed for purifying large-size targets such as viral antigens, vectors and VLPs.
Conventional chromatography media with standard pore sizes can only adsorb FMD viral antigens and VLPs on their outer surfaces. In contrast, our super-pore media enable adsorption both on the outer surface and inner pore surfaces. Featuring extremely low mass transfer resistance, the media achieve full adsorption of viral antigens and VLPs.
Process 2: His-Tag Affinity Chromatography (for Recombinant VLP Vaccines)
For His-tagged recombinant proteins expressed in Escherichia coli, our affinity chromatography media deliver outstanding pressure resistance and anti-fouling performance. They can efficiently capture His-tagged fusion proteins from cell lysates and culture broths, with abundant successful application cases for purifying VLP-forming His-tagged fusion proteins.
Process 3: Mixed-Mode Chromatography (for Inactivated Vaccines)
Mixed-mode chromatography media are also available for the purification of inactivated FMD vaccines. Adopting a core-shell structure, the outer shell is composed of hydrophilic polymers with tailored pore sizes.
Large-sized viral particles and macromolecular proteins flow through the media via size exclusion, while small impurities penetrate the shell into the inner core and are captured by the core through combined ion exchange and hydrophobic interaction. Integrating size exclusion and adsorptive effects, this technology realizes one-step separation of viral particles/macromolecular proteins from impurities, delivering far higher purification efficiency and operability than traditional media.
Conclusion
As China enters a critical stage of SAT1 FMD prevention and control, vaccine quality is the lifeline of disease prevention.
Equipped with chromatography media featuring high rigidity, super-large pores, high binding capacity and high flow rate, as well as scalable mature processes, Sino Bioengineering provides one-stop purification solutions for both inactivated FMD vaccines and recombinant VLP vaccines. We assist manufacturers in rapidly stabilizing production, improving quality and boosting efficiency, and work together to safeguard the biosafety of China’s animal husbandry industry.
