Introduction to Foot-and-Mouth Disease Synthetic Peptide Vaccine

Foot-and-mouth disease (FMD) synthetic peptide vaccine is a new type of veterinary vaccine developed based on peptide technology, primarily used to prevent and control foot-and-mouth disease virus (FMDV) infection. FMDV is a highly contagious virus that mainly invades cloven-hoofed animals such as pigs, cattle, and sheep. It spreads rapidly with a high incidence rate, which not only leads to hindered growth and reduced production performance of livestock and poultry but also causes huge economic losses to the animal husbandry industry. Meanwhile, it is listed as a notifiable disease by the World Organization for Animal Health , triggering trade restrictions from disease-free countries on regions with outbreaks. Therefore, this type of vaccine is one of the core products for livestock and poultry epidemic prevention and a typical application achievement of peptide technology in the field of veterinary biology.

Through automatic solid-phase peptide synthesis technology, key antigenic epitopes on the surface of FMDV (mainly neutralizing epitopes of the VP1 structural protein) are accurately screened and synthesized. At the same time, combined with the Th cell epitope binding library, the natural three-dimensional conformation of the virus is simulated with technologies such as click chemistry. Without containing complete virus particles, it can accurately activate the specific immune response of the animal body, induce the production of high-efficiency neutralizing antibodies and specific T cells, and achieve precise prevention and control of the virus. It is equivalent to presenting a "virus identification code" to the animal's immune system, which is both efficient and safe, meeting the core requirements of DIVA (Differentiating Infected from Vaccinated Animals) vaccines.

Compared with traditional inactivated FMD vaccines, it has prominent core advantages, which can effectively solve many pain points of traditional vaccines:

1. High Safety: It does not contain complete viruses or heterologous proteins, and no inactivating agents are used in the production process, eliminating potential risks such as virus escape, virulence reversion, and virus spread that may occur in the production of traditional vaccines from the source. Clinical applications have shown that almost no adverse reactions such as allergies and fever occur after immunization with this vaccine, and it has no adverse effects on sensitive groups such as pregnant sows and weaned piglets, and even does not cause abortion in pregnant sows. At the same time, it can reduce the impact of immune stress on the growth performance of livestock and poultry. After immunization, livestock and poultry have normal feed intake, and their average daily gain and feed conversion rate are better than those of groups immunized with traditional vaccines.
2. Better Immune Effect: The antigen content is precisely controlled by an automatic synthesizer, combined with imported adjuvants or new delivery systems. After immunization, the antibody level is high and the duration is long, with the antibody positive rate reaching 100% after the second immunization, and the antibody level can be stably maintained until the animals are slaughtered. This vaccine has broad-spectrum cross-protection against prevalent FMD type O strains (such as Mya-98 lineage, CATHAY topology, etc.), and can still achieve 100% clinical protection 6 months after a single immunization. Currently, the internationally advanced B2T-TB2 dendritic molecule synthetic peptide vaccine can provide complete protection for pigs with a single low dose of 0.5mg, and achieve cross-neutralization within the type O serotype.
3. Accurate Differentiation between Infection and Immunization: The vaccine only contains specific peptide antigens and does not contain FMDV non-structural proteins (such as 3ABC). Through supporting ELISA antibody detection kits (such as the FMD type O virus competitive ELISA antibody detection kit approved and registered by the Ministry of Agriculture and Rural Affairs), it can quickly and accurately distinguish between "vaccinated animals" and "naturally infected animals", helping with the purification of livestock and poultry epidemics and the construction of immune-free areas. This is one of the core advantages that traditional inactivated vaccines cannot achieve, and it is  great significance for emergency response and safe resumption of trade in global disease-free areas.
4. More Convenient Production and Storage: Adopting chemical synthesis technology, the production cycle is short, without relying on cell culture, which can quickly respond to virus mutations and adapt to the prevention and control needs of multiple serotypes and subtypes of the virus. The vaccine has strong quality stability, can be stored at 2℃—8℃ for 36 months, and the immune efficacy can still reach 100%. Moreover, the vaccination dose is small (usually 1ml), which is easy to store and transport, effectively reducing epidemic prevention costs and transportation losses.

At present, the mainstream domestic products in China are mainly synthetic peptide vaccines against foot-and-mouth disease type O for pigs. Among them, the product developed by Shenlian Biomedical (Shanghai) Co., Ltd. is the first synthetic peptide vaccine in China to obtain the "Class I New Veterinary Drug Certificate" from the Ministry of Agriculture. It was put on the market as early as 2007 and included in the government bidding and procurement list. Subsequently, it has been iterated into bivalent synthetic peptide vaccines of type O and type A, covering a wider range of virus strains; Other enterprises  have also launched related products, which are widely used in livestock and poultry epidemic prevention across the country and enjoy extremely high market recognition.