RT Journal Article SR Electronic A1 Horáková, Dagmar A1 Štěpánek, Ladislav T1 Highly contagious infections of our age JF Profese Online YR 2021 VO 14 IS 2 SP 6 OP 9 DO 10.5507/pol.2021.013 UL https://profeseonline.upol.cz/en/artkey/pol-202102-0008.php AB Highly contagious infections (HCI) have common characteristics, namely a serious clinical course with relatively high mortality and high infectivity with a significant potential for rapid spread in the human population. Clinical units belonging to HCI can meet both characteristics at the same time or only one of them. Changes in the environment and in the way humankind behaves help the emergence and spread of HCI. Anti-epidemic measures for the management of HCI are generally divided into preventive and repressive. In the 21st century, three new HCI of coronavirus etiology and zoonotic origin have occurred, causing respiratory diseases (SARS, MERS, Covid-19), with various mortality. Covid-19 is the third highly pathogenic human coronavirus infection. Although it has the lowest mortality, it has shown a tremendous ability to spread rapidly in the susceptible population and has become the most serious health threat in modern history. The struggle against the disease is complicated by the high proportion of asymptomatic carriers, the epidemiological significance of whom for the spread of the disease has not been fully elucidated. So far there has been a lack of information on the duration of immunity after infection or vaccination.