Usually, the most common symptoms in people with variola virus infection are fever, cough, malaise, and local or generalized pain. Fever, in particular, is itself an immune response triggered by viral or bacterial infection, and a small number of patients may experience specific reactions such as chest tightness, nausea, vomiting, yellowing, and wasting, depending on the type of virus. In addition, mutated viruses are upgraded versions of the original virus and are usually more virulent, resulting in more pronounced discomfort, faster onset and more life-threatening infections. Some mutated viruses are even immune to vaccines or antibodies present in the body, making vaccination or drug treatment ineffective. The new coronaviruses that are currently prevalent also have mutated viruses, such as delta, beta, ramada, mu strains, etc. The common features of these viruses are more infectious, faster transmission, higher viral load, more rapid onset and higher mortality, which in turn require the attention of the general public. Therefore, patients coming from foreign infected areas, or medium or high risk areas in China should cooperate with isolation and active nucleic acid testing to prevent carrying the virus in their bodies from causing others to infect them. In case of abnormal discomfort, patients should seek medical attention for differential diagnosis so that early treatment measures can be taken.