Vimentin, an intermediate filament protein that is typically part of the cell cytoskeleton. Vimentin is usually located inside the cell, but under pathological conditions such as viral infection, cellular stress, or apoptosis, it can be translocated and expressed on the cell membrane surface. This abnormal cell surface expression makes it a potential target for therapeutic intervention. In virus-infected cells, surface-exposed Vimentin is thought to be involved in viral entry, budding, or immune evasion processes. Burfiralimab targets the Vimentin expressed on the surface of infected cells, providing a selective way to recognize and neutralize virus-infected cells without harming healthy cells. Its IgG4 isotype suggests its primary role is neutralization or blockade rather than strong cytotoxic clearance. In COVID-19, it aims to improve patient outcomes by clearing infected cells and reducing virus-induced inflammation.