Something about clotting/thinning being a problem for pulmonary issues with the 1918 flu and possibly with this one too. IIRC it related to cytokine storm issues.
Found interesting document concerning corticosteroids, ascorbic acid, and thiamine cooperation to counter viral related toxic chemicals shutting down cellular mitochondria. The most important action may relate to ascorbic acids (vitamin c) antioxidant action to regenerate vital chemical processes for energy production within the body’s cells.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6265973/