According to data from a recent study on the Delta virus published by the Centers for Disease Control and Prevention on its official website, the virus can have a detoxification period of up to 18 days. The Delta strain is currently the main mutant strain in the global new coronavirus epidemic. According to the CDC, the Delta strain is characterized by high viral load, high transmission capacity, rapid transmission and long turnaround time: 1. High viral load: a significant increase in viral load in patients compared to previous strains means an increase in the severity of the disease in those infected with the Delta virus and a higher probability of turning into a critically ill type The ability to spread is enhanced because of the high viral load and the increased concentration of exhaled virus in delta patients. The same space, the same unit, the same building, and those who get along with the patient four days before the onset of the disease are close contacts; 3. Fast transmission: Delta virus spreads extremely fast, as short as 14 seconds. The corresponding incubation period has been shortened, and the disease can develop within 24 hours; 4. Long time to turn negative: Because of the high load of delta virus, the concentration of virus in the patient’s body increases after infection, and it is more difficult to control the disease and achieve negative turn than before. According to the domestic situation, the proportion of unvaccinated patients in the population infected with delta virus is significantly higher than that of vaccinated patients. Even after vaccination, the likelihood of becoming seriously ill or critically ill is greatly reduced, indicating that the New Crown vaccine is still effective against the delta strain. With good protection and active vaccination, infection with delta virus can be attenuated or avoided.