Adbiotech Confirms Efficacy of H9N2 Low Pathogenic Avian Influenza Antibody Therapeutic

Adbiotech, a company specializing in immune antibodies, announced on January 16 that it has confirmed the efficacy of oral administration for its Y280 lineage H9N2 low pathogenic avian influenza (AI) antibody prophylactic and therapeutic agent, 'Anti-H9 ScFv'.

Adbiotech has focused on passive immunity-based antibody therapeutics that can address the limitations of conventional vaccines. 'Anti-H9 ScFv' is a single-chain antibody (scFv)-based substance designed to induce an immediate immune response at the early stage of infection by directly administering pre-formed antibodies into the body.

This efficacy evaluation was conducted by adding Anti-H9 ScFv to the feed of laying hens for oral administration, then analyzing changes in antibody responses to the H9 AI virus antigen. The degree of antibody production was measured using enzyme-linked immunosorbent assay (ELISA) before administration, and at the second and fourth weeks after administration.

The experiment confirmed an increase in blood antibody titers even at the second week after administration. At the fourth week, antibody levels were approximately 30-40% higher compared to pre-administration. Oral administration of Anti-H9 ScFv was found to stimulate the chickens' immune system, increasing the production of Anti-H9 antibodies in response to the H9 AI virus, and demonstrated an immune-enhancing effect against the H9 antigen.

A representative from Adbiotech stated, "It is significant that we have confirmed the effectiveness of the antibody therapeutic for responding to low pathogenic AI," adding, "Through further research, we plan to enhance its field applicability and continue developing it as a new disease control measure to supplement vaccines."

H9N2 low pathogenic AI is a disease that causes decreased laying rates in laying hens and reduced productivity in broiler breeders, resulting in economic losses for poultry farms. In particular, broiler farms have seen considerable damage due to frequent cases of mixed infections with infectious bronchitis (IB). There is also a risk that low pathogenic AI could mutate into a highly pathogenic virus, underscoring the need for ongoing management and countermeasures to prevent farm-to-farm transmission.

In Korea, H9N2 low pathogenic AI vaccines have been used for infection control since 2007, but since 2020, the spread of Y280 lineage variant viruses, which differ from existing vaccine strains, has led to reduced protective efficacy. New vaccines have limitations, as intramuscular administration and a single dose are insufficient for adequate protection, making their application limited for broilers with short rearing periods.

The absence of a dedicated therapeutic also poses a limitation, as farms must rely on general antiviral agents. Antiviral drugs are associated with issues such as the development of resistance and cost burden.