Why SARS-CoV-2 replicates better in the upper respiratory tract

First authors Silvio Steiner ( bottom left ), Jenna Kelly ( top left ), Mitra Gultom ( top center ), Philip V'kovski ( top right ), and corresponding author Ronald Dijkman ( bottom right ), Institute for Infectious Diseases (IFIK), University of Bern. UniBE - A team of researchers from the Institute for Infectious Diseases (IFIK) at the University of Bern and the Federal Institute of Virology and Immunology (IVI) have assessed virus growth and activation of the cellular defense mechanisms in the respiratory tract. They have shown that natural temperature differences that exist in the upper and lower respiratory tract have a profound influence on SARS-CoV-2 replication and subsequent innate immune activation in human cells. The findings can help to develop antiviral drugs and preventive measures. SARS-CoV-2 and SARS-CoV are highly similar genetically, generate a homologous repertoire of viral proteins, and use the same receptor to infect human cells. However, despite these similarities, there are also important differences between the two viruses', says Ronald Dijkman from the Institute for Infectious Diseases (IFIK) at the University of Bern. For example, SARS-CoV infection is characterized by severe disease and inflammation in the lower respiratory tract and infected individuals are only contagious after the onset of symptoms, making it easier to identify and interrupt infection chains. "SARS-CoV-2 and SARS-CoV are highly similar genetically, generate a homologous repertoire of viral proteins, and use the same receptor to infect human cells.