C5AR1 and COVID-19: However, the mechanism by which targeting C5–C5a–C5aR1 or GCS-glycosphingolipid pathways inhibit the viral replication, and the induction of immune inflammation remains unknown; thus, additional in vitro, ex vivo, and in vivo studies on different variants of SARS-CoV-2 (e.g., Alpha, Beta Delta, BA.4, and BA.5)-induced COVID-19 are required.