Americans created the deadly coronavirus five years ago," - such headlines are flashing here and there for the last few days regarding the article in the Nature magazine from 2015. Researchers from the University of North Carolina in the USA focus their study on SHC014-CoV - SARS-like coronavirus infecting horseshoe bats discovered in 2013. A study of Chinese experts shows that the virus had appeared as a result of recombination of lines, which also led to the appearance of SARS-CoV. In 2015, scientists along with colleagues from the Wuhan Institute of Virology created a "chimeric" virus based on surface protein SHC014 and SARS virus. The study shows that SHC014 has all essential tools for binding to a key cell of a human. The experiment confirmed the hypothesis of the possibility of direct human infection with bat coronaviruses. New virus could infect airway epithelium of a human lung, as well as cancer cells. In experimental mice, the virus caused pneumonia, loss of up to 10% of body weight was observed. Fatalities were rare and only in old mice (12 months and older). This coronavirus may be chosen as an object for creating the perfect design for infection, - explained the Russian specialist in virus genetics who preferred to stay anonymous. - Being respiratory virus, it spreads effectively (second only to measles virus in its potential). Its genome has a large number of genes, which is notoriously convenient. The main downside is in a special combination: the pathogen is respiratory and asymptomatic at early stages. It has a prolonged incubational period. This is the most dangerous combination possible. As the specialist explained, coronavirus takes control of the first phase of infection. During first stages it's able to suppress the immune response of an organism it infected. When the number of copies exceeds a certain level, immune system is triggered, but in the form of a systemic immune response. This response is so massive and strong, that it leads to lung damage. By the time the symptoms appear, the virus is already present in almost every cell of a human. As a result, the immune system provides such a strong response that it leads to (among other damage) a pulmonary edema, lung volume is reduced to a bare minimum, making effective breathing nearly impossible.