The definition of neocoron is still a novel coronavirus infection in general, as for the latest definition it generally refers to a mutated strain of a novel coronavirus. The details are described below: Novel coronaviruses are new strains of coronaviruses that have never been found in humans before and can cause colds as well as Middle East Respiratory Syndrome and Severe Acute Respiratory Syndrome. Common symptoms of human infection with novel coronaviruses include fever, cough, shortness of breath and difficulty breathing. In more severe cases, infection can lead to pneumonia, severe acute respiratory syndrome, kidney failure, and even death. The transmission of novel coronaviruses is characterized as highly infectious and insidious. The most recent definition generally refers to mutated strains of novel coronaviruses. on November 24, 2021, it was reported that scientists had warned of the dominance of a Delta variant of a new coronavirus mutation that carries an “extremely large number” of mutations. In the same year, the World Health Organization held a special meeting and announced that the new coronavirus strain B.1.1.529 reported in southern Africa had been labeled as a “variant of concern” and named with the Greek letter Ο (Omicron), which is now widely circulated as the Omicron variant. This is the now widely circulated Omicron variant strain.