Wettstein et al demonstrated that A1AT can inhibit SARS-CoV-2 infections in human cells in vitro. Caco2 and Vero cells were treated with different concentrations of A1AT and were later infected with SARS-CoV-2 using pseudoparticles that contained viral S protein as well as wild type virus. It was observed that infection was almost completely inhibited when cells were treated with 2 to 4 mg/mL, which is within a normal physiological range. Additionally, no toxic effects were observed in the cells that were treated with a high dosage of 8.2 mg/mL. This suggests that A1AT may have potential as a future COVID-19 therapeutic.