C5 and COVID-19: Similarly, C5a-suppressing oral treatments (e.g., Avacopan, approved for the treatment for anti-PMN cytoplasmic antibody-associated vasculitis) and the pharmaceutical targeting of the GCS (e.g., Venglustat, which inhibits the synthesis of glycosphingolipids) can be used as potential approaches to control the tissue inflammation, organ failure, and death in patients with COVID-19 and GD patients with COVID-19 experiencing uncontrolled infections with different variants of SARS-CoV-2 (e.g., Alpha, Beta Delta, BA.4, and BA.5) [354,355].