The results showed that Biobran is a potent anti-COVID-19 agent: it significantly inhibits ACE2–SARS-CoV-2 S-protein RBD binding, it significantly suppresses SARS-CoV-2 gene expression and protein levels, and it has a significant cytotoxic effect on Vero E6 cells with a high selectivity index. Here, ACE2 is linked to COVID-19.