Abstract: The present invention relates to an inhibitory agent of membrane fusion between a virus envelope and a cell membrane of a host cell for the virus, wherein the inhibitory agent comprises a serine protease inhibitor, and a therapeutic agent or a therapeutic composition, comprising the inhibitory agent. More specifically, the present invention relates to the inhibitory agent, wherein the serine protease inhibitor is one or more of a compound represented by the following general formula (I) or a salt thereof, or a solvate or hydrate thereof, and a therapeutic agent or a therapeutic composition, comprising the inhibitory agent: wherein R1 represents a substituted or unsubstituted lower alkyl group, a substituted or unsubstituted lower alkenyl group, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted aromatic heterocyclic group, each of which may optionally comprise a heteroatom.

Abstract: Anti-SARS-CoV-2 fusion peptides are provided. The anti-SARS-CoV-2 fusion peptides include peptide sequences corresponding to the sequence of the SARS-CoV-2 fusion complex heptad repeat domain HR2 and having at least one artificial mutation. The anti-SARS-CoV-2 fusion peptides may be 39-mers, such as peptides #121 (SEQ ID NO: 2) and #125 (SEQ ID NO: 5). These peptides may competitively bind to SARS-CoV-2 and prevent either membrane mediated SARS-CoV-2 fusion, endocytosis-mediated viral entry, or both. The anti-SARS-CoV-2 fusion peptides may be administered to a subject in need thereof to inhibit or prevent SARS-CoV-2 cellular entry.

Abstract: Anti-SARS-CoV-2 fusion peptides are provided. The anti-SARS-CoV-2 fusion peptides include peptide sequences corresponding to the sequence of the SARS-CoV-2 fusion complex heptad repeat domain HR2 and having at least one artificial mutation. The anti-SARS-CoV-2 fusion peptides may be 39-mers, such as peptides #121 (SEQ ID NO: 2) and #125 (SEQ ID NO: 5). These peptides may competitively bind to SARS-CoV-2 and prevent either membrane mediated SARS-CoV-2 fusion, endocytosis-mediated viral entry, or both. The anti-SARS-CoV-2 fusion peptides may be administered to a subject in need thereof to inhibit or prevent SARS-CoV-2 cellular entry.