Since February, the world has known that the coronavirus infection affects men more seriously than women. Regardless of the fact that the risk of infection is equal for both sexes, in the strong half of humanity, the probability of developing a severe form of COVID-19 and a fatal outcome is much higher. This conclusion was also made by the Chinese doctors, who even then began research into the probable causes of the difference. Now the conclusion is confirmed by the Western medical community. The analysis covers the data of over a thousand patients with covid. In addition, more than 500 cases of patients with SARS – severe acute respiratory syndrome, archived from the 2003 outbreak, which was justified by the similarity of the causative virus, were also examined. Regardless of age, the disease is equally common in both sexes. For example, in our country as of April 24, there were 585 registered cases of men with covid and 603 of women.1 But the risk of a fatal outcome for men is 2.5 times higher than for women, according to all surveys conducted so far. The severe form of the disease is much more common in men. According to the researchers, the angiotensin-converting enzyme 2 – ACE2, with which the coronavirus binds during infection, is found in a much larger amount in the male body than in the female. Higher numbers of ACE2 are also reported in certain risk groups, such as those suffering from hypertension and diabetes. Men are generally more vulnerable to viral infections – this is not a new fact for medicine. They experienced a more severe course of SARS and Middle East respiratory syndrome (MERS) in 2003 and 2015, respectively. In 2003, more women fell ill from SARS, but 50% more men lost their lives. In MERS, the mortality is respectively: 32% in the strong and 25.8% in the fair sex. Due to COVID-19, these numbers are 2.8% and 1.7%. A similar ratio is also observed in the available data for the pandemic wave of Spanish flu in 1918.2 Research in this direction will continue until this mystery is resolved. For now, it can be argued that women have a more pronounced immune response after vaccination and immune memory. However, women’s stronger immunity comes at a price, Dr. Janine Clayton, director of the NIH’s Division of Women’s Health Research told The New York Times, and that is their higher incidence of autoimmune diseases. It is assumed that this is an advantage of the female organism, developed in the course of evolution, which helps the survival of the offspring. Antibodies are known to be passed from the mother to the fetus before pregnancy and later after birth through her breast milk to the baby. Another possible cause is the influence of estrogen and the presence of two X chromosomes, which contain genes important for the immune system. In addition to the biological prerequisites, lifestyle is also important for the form of the disease in the representatives of both sexes. Patients with type 2 diabetes, hypertension and COPD are much more often men. The presence of these diseases makes the coronavirus infection with complications.Women are the ones who more often seek a doctor, while for men there is known a certain resistance and later receiving medical help due to neglect of the condition. A later diagnosis of COVID-19 is much more likely to have developed pneumonia. Bibliography: 1. https://www.mh.government.bg/bg/novini/aktualno/1188-sa-potvrdenite-sluchai-na-covid-19-u-nas/ 2. https://www.ncbi. nlm.nih.gov/pmc/articles/PMC2740912/ 3. https://www.nytimes.com/2020/02/20/health/coronavirus-men-women.html 4. https://medicalxpress.com/news /2020-04-covid-men-death-women.html 5. https://www.frontiersin.org/articles/10.3389/fpubh.2020.00152/full