The longer the COVID−19 coronavirus pandemic lasts, the more information about its clinical manifestations is accumulated. The incubation period of COVID−19 ranges from 2 to 14 days, rarely up to 3 weeks, but in a significant number of cases an infection is not accompanied with the appearance of clinical symptoms. Currently, the following variants of the clinical course of COVID−19 can be identified as follows: viral load; subclinical; slight; uncomplicated with damage to only the upper respiratory tract; mild pneumonia, severe pneumonia, acute respiratory distress syndrome, etc. The clinical course of COVID−19 depends on the severity, the criteria of which are the intoxication manifestation, the degree of fever and the dominant syndrome. Mild / moderate forms are manifested by frequent increase in body temperature up to 38 ° C, respiratory symptoms, headache, myalgias, palpitations and general malaise. Patients stop distinguishing smells and feel the taste of food. Approximately from the 7th to the 9th days of the disease there are problems with breathing, which indicates the impairment of the lower respiratory tract and the beginning of the second phase of the disease, and its course is regarded as severe. Severe forms of the disease can also be manifested by impaired coordination of movements, slurred speech. In 1 to 4 % of patients there is developed the psychosis in the form of hallucinations. In the elderly, COVID−19 may be accompanied by delirium, lowering blood pressure. The risks of adverse disease are associated with somatic diseases: cardiovascular and nervous systems, respiratory tract, hormonal disorders, etc. Otitis, sinusitis, sepsis, bronchopulmonary infection, thrombosis, myocarditis etc. can be the complications of COVID−19. Computer tomography is an instrumental test that demonstrates the damage of lungs with coronavirus and allows to assess its severity. Key words: coronavirus infection, COVID−19, clinical variants, severity, pneumonia, acute respiratory distress syndrome.