Universal Antibody Test to Detect SARS-CoV-2 Exposure in Animals Developed

It is now possible to detect exposure to the SARS-CoV-2 virus in any animal species. The development of a universal antibody test, reported in mSphere, allows researchers to track coronavirus variants in both wild and domesticated animals. Unlike traditional antibody tests that require specialized chemical reagents for each species, this new test focuses on detecting antibodies against a protein called the N-protein, which is present in the virus's nucleocapsid.

The N-protein is abundant and highly conserved across species, making it an ideal target for all-species antibody tests. The test utilizes a blocking ELISA protocol, where an ELISA plate is coated with the N-protein and serum samples from animals are added. If the animal has been infected with the coronavirus, its serum will contain anti-N-protein antibodies that will bind to the coated plate. The presence of these antibodies is then detected using a secondary biotin-tagged monoclonal antibody. If the animal is positive for coronavirus infection, its antibodies will block the secondary antibodies from binding to the N-protein, indicating a positive result.

The researchers validated the test using samples from animals with known SARS-CoV-2 infection status, demonstrating a sensitivity of over 97% and specificity of 98%. Further tests on domestic cats showed that the assay could detect infection within seven days of exposure to the virus.

This development is crucial for tracking coronavirus variants in animals and identifying potential new animal reservoirs. It provides scientists with a valuable tool for field surveillance in animal populations, helping to prevent future disease outbreaks by understanding the spread and evolution of the virus in different species.

The research was led by Ying Fang, a pathobiology professor and virologist at the University of Illinois Urbana-Champaign.