Molecular Mechanisms of the Medicines for COVID-19

For these three years, COVID-19 has globally spread and caused enormous damage all over the world. Although vaccines served to reduce its infection, their effects are still limited mainly due to rapid and vigorous mutations of SARS-CoV-2 virus. In order to bring this pandemic under control, we must develop novel medicines which are easily administered when needed and very effective without undesired side-effects. In this account, the developments of specific medicines for COVID-19 are surveyed with the emphasis on the molecular mechanisms of their therapeutic actions. Most of them are inhibitors of enzymes, which are indispensable for the virus, but unnecessary for human beings. These inhibitors selectively hamper the critical steps for viral proliferation (viral entry to human cells, replication of RNA genome, production of viral proteins, and others). There have been several successful examples, which are already approved as medicines for the treatment of COVID-19. Unfortunately, however, few of them sufficiently satisfy all the requirements to overcome this unprecedented pandemic completely, and thus further innovation is necessary.