Close contacts should have multiple negative nucleic acid test results during the 21-day isolation observation to be considered fine. According to the “Program for Prevention and Control of Novel Coronavirus Pneumonia (Eighth Edition)”, close contacts should undergo 14 days of centralized isolation for medical observation, with one nucleic acid test on each of the 1st, 4th, 7th, and 14th days, which is negative, then it can be changed to home quarantine for 7 days, and one nucleic acid test on each of the 2nd and 7th days of home quarantine, which is negative, before it can be released from quarantine. As the incubation period of CKP is usually around 3~7 days, and can be as long as 14 days, there are also a few cases that develop only after 20 days or more, and the onset of disease varies according to the individual’s physical condition. The virus is still contagious during the incubation period, so it is necessary to carry out centralized isolation for 14 days, and after the conditions for lifting the centralized isolation have been met, then carry out home isolation for 7 days and regular nucleic acid testing to prevent the onset of the disease after 14 days. Therefore, whether close contacts are fine or not should be determined by the results of nucleic acid testing during the 14-day centralized isolation and the 7-day home isolation, and the isolation can only be lifted if the results are both negative. It is recommended that during the epidemic, try not to go to high-risk areas and places where people gather, pay attention to wearing masks, more exercise, improve immunity. Tip: “New coronavirus pneumonia” and “new coronavirus pneumonia” mentioned in this article were renamed to “new coronavirus infection” on December 26, 2022, as announced by the National Health Commission.