ACE2 and viral infectious disease: Importantly, the antiviral mechanisms of ALD-R491 create multiple novel actions against viral infection—first, a blockade of spike protein and ACE2-mediated endocytosis and of endosomal trafficking and exosomal release, which are the cellular processes that are unlikely to be evaded by the virus even with mutations, and second, an enhanced ability of macrophages to kill pathogens, which is critical both for containing the viral spread at early stages and for clearing persistent viral presence after the acute phase of infection.