The incubation period of neo-coronavirus is generally 1-14 days, in most cases 3-7 days, and may exceed 14 days in a very small number of infected individuals. In addition, some strains of neocoronavirus variants, such as Delta, have a shorter incubation period than that of the common neocoronavirus, mostly 1-3 days. The incubation period may be shorter in some patients because of their own physical condition and environment. 1. Physical condition: some patients may have underlying diseases such as asthma, diabetes, heart disease, etc., or the elderly may have a weakened organism, which may lead to a shorter incubation period. If you are in a high-risk group such as close contacts of the infected person, you are more likely to be infected with novel coronavirus, and the viral load is high and the degree of infection is heavy, so the disease progresses faster and the incubation period will be shortened accordingly. Therefore, if the diagnosis of novel coronavirus infection is also confirmed after nucleic acid testing and a high degree of homology of the viral gene sequence, the infected person during the incubation period may not have any symptoms, but there is already infectivity, so isolation for treatment is also required. The earliest symptoms in patients with novel coronavirus infection after the incubation period are mainly fever, dry cough, malaise, and in a few cases, sore throat, muscle pain, abdominal pain, diarrhea, and other symptoms. Therefore, once suspicious symptoms occur, they should be promptly reported and isolated for medical consultation; the earlier the treatment, the lower the risk.