The list of the pockets of the drugs and the pockets of COVID-19 were feed to PocketMatch algorithm which works by representing each Binding site by a 90 list of sorted distances capturing the shape and chemical nature of the pocket, the sorted arrays are then aligned using an incremental alignment method and score them obtain PMscore for a pair of pockets. This algorithm is fast and only takes 1/125 for a single comparison. The calculation carried on a Linux virtual machine (4GB ram and single processor 14GB disc space), and due to the limited computational power, the similarity calculation was separated into 3 batches. PocketMatch gave two similarity measures Pmin and Pmax. In this study, Pmax was used which takes the global similarity into account and it's more strict. Pmin was ignored as the PocketMatch created said: "it's too optimistic".