Inhibition of influenza A virus and SARS-CoV-2 infection or co-infection by griffithsin and griffithsin-based bivalent entry inhibitor

Outbreaks of acute respiratory viral diseases, such as influenza and COVID-19 caused by influenza A virus (IAV) and SARS-CoV-2, pose a serious threat to global public health, economic security, and social stability. This calls for the development of broad-spectrum antivirals to prevent or treat infection or co-infection of IAV and SARS-CoV-2. Hemagglutinin (HA) on IAV and spike (S) protein on SARS-CoV-2, which contain various types of glycans, play crucial roles in mediating viral entry into host cells. Therefore, they are key targets for the development of carbohydrate-binding protein-based antivirals. This study demonstrated that griffithsin (GRFT) and the GRFT-based bivalent entry inhibitor GL25E (GRFT-L25-EK1) showed broad-spectrum antiviral effects against IAV infection