Coronavirus appeared as an unexpected gift for the New Year 2020 and in a few months the world turned into a disaster series. Through incredible efforts, the state stopped the spread of the virus, but already in the fall the epidemic began to gain momentum again. What do we know about SARS-CoV-2, why it kills some and is asymptomatic in others, is the vaccine safe and when will a cure be found, how do we treat COVID- 19 without it, is it possible to fight a pathogen without shutting down the planet - the book answers these and many other questions. Although the pandemic is not over yet, and we are constantly learning new data about the virus, the fundamental principles outlined in the text will no longer change: they serve as a framework on which the reader can string new knowledge.