"We have been studying and adjusting the prevention and control measures to protect the people's interests to the greatest extent and minimize the impact of the epidemic on economic and social development." At the press conference of the joint prevention and control mechanism of the State Council on November 29, Mi Feng, spokesman of the National Health Commission and deputy director of the Propaganda Department, made the above response when responding to the questions of media reporters about "whether China will reconsider the COVID-19 prevention and control policy". Mi Feng said that since the outbreak of the epidemic, the Chinese government has been making prevention and control, research, summary and adjustment at the same time according to the characteristics of the virus mutation and the practical understanding of clinical treatment, including the characteristics of the transmissibility and pathogenicity of the Omicron mutation, as well as the severity and mortality rates, paying close attention to the changes in some international epidemic situations. Cheng Youquan, director of the First Supervision Department of the National Bureau of Disease Control and Prevention, pointed out that each of the 20 optimization measures has sufficient scientific basis and evidence support, and should adhere to the "ninth edition" and implement the 20. For some possible risk links, the integrated team of the joint prevention and control mechanism has specially formulated four technical documents, including nucleic acid detection, risk zone delimitation and control, home isolation medical observation, and home health monitoring, and proposed preventive and response measures. As long as strict implementation is in place in all regions, epidemic risk can be effectively reduced. Long term closure has a great impact. In response to the reporter's question that "long-term closure in some places has had a great impact on the work and life of the masses, causing anxiety among the masses", Cheng Youquan said that this situation must be corrected and avoided. All localities should further strengthen the training on the criteria for the division of high-risk areas and low-risk areas, and organize the delineation and management of risk areas. In principle, high-risk areas are generally defined by units and buildings, and should not be expanded at will. When the risk of epidemic transmission is not clear or there is widespread community transmission, the scope of high-risk areas can be appropriately expanded, but it is necessary to pass nucleic acid screening and epidemic research and judgment in a timely manner to quickly seal and resolve. "It is not allowed to expand the judgment scope of risk personnel through time and space." Cheng Youquan stressed that the judgment should be based on the on-site investigation, and should not cause large-scale "accidental injury", so as to minimize the inconvenience caused by the epidemic. High risk areas should be strictly controlled and managed to "stay at home", and we should also make every effort to do a good job of service guarantee to meet the basic living needs of the people and medical needs. At the same time, we should do a good job of persuading the isolation personnel, increase the care and help for special groups such as the elderly, the infirm, the disabled and the pregnant, and solve the actual difficulties of the people. The elderly are at high risk of severe disease. Guo Yanhong, Director of the Medical Emergency Department of the National Health Commission, should strengthen vaccination. From the practice of clinical medical treatment of COVID-19, the elderly over 60 years old are at risk of severe disease after COVID-19 infection, and the elderly over 80 years old are at risk of severe disease. The data shows that 181.511 million people over 60 years old have completed intensive immunization, including 27.426 million people over 80 years old. 23.563 million people have completed the whole process of immunization, accounting for 76.6% and 65.8% of the people over 80 years old respectively