In fact, the comparisons with genetic data of various populations indicated the remarkably high frequencies in the Vietnamese population of some essential actionable variants relating to the COVID-19 drug, including the VKORC1 variants which request adjusted dosing of the VKAs, the CYP2C19 no-function alleles which lead to impaired excretion of voriconazole, or the HLA alleles associated with severe cutaneous adverse reactions when using trimethoprim/sulfamethoxazole. Here, CYP2C19 is linked to COVID-19.