Researchers identify proteins that contribute to the pathogenicity of COVID-19 virus Researchers at Texas Biomedical Research Institute (Texas Biomed) have narrowed down the proteins enabling SARS-CoV-2 to cause disease. Using advanced genetic engineering techniques developed at Texas Biomed, they systematically deleted the genetic code for five of the virus's accessory proteins, one at a time, to see how each one affected the virus's ability to spread and cause illness. The research was published online this month in the Journal of Virology. They found two proteins that seem to contribute most to the virus's pathogenicity, or ability to cause COVID-19 disease. When individually lacking those proteins, the virus did not replicate as much as the natural virus in cells, suggesting they play a critical role in its spread. In contrast, spread was not significantly reduced when the other proteins were deleted.