Recently, the World Health Organization introduced two new autovariants of Omicron ba 4、BA. 5 has been included in the detection list, Xe recombinant virus has also accelerated the spread all over the world, and XD, XL and other strains have also appeared one after another. As COVID-19 continues to mutate, will its speed of transmission be further accelerated? According to the situation and characteristics of this round of national epidemic, what are the tips for the next epidemic prevention and control? At the press conference of the joint defense and joint control mechanism of the State Council held in April 19th, Wu Zunyou, chief expert of China's CDC epidemiology, said that COVID-19 mutation has been continuously occurring. Some of the mutations have changed their biological characteristics, affecting their infectious, pathogenic and immune escape abilities. Some people believe that COVID-19 is mutated toward infectious enhancement and diminished pathogenicity. Is that true? Wu Zunyou said that in fact, from a biological point of view, there is no essential connection between infectivity and pathogenicity. The reverse relationship between these two aspects is more determined by people's sociological attributes. "When the pathogenicity is weakened, the symptoms of infected people are mild, they have more time for social activities, contact more people, and cause more people to be infected." Wu Zunyou said that at present, there is no obvious rule of COVID-19 mutation in infectious, pathogenicity and so on. It is possible to develop in the direction of infectious enhancement and pathogenicity weakening, and it may also enhance the direction of infectious enhancement and pathogenicity. So what should we do with COVID-19, which is constantly changing? Wu Zunyou suggested: on the one hand, it is necessary to closely track the changes and progress of new variant strains in terms of transmission range, infectivity and pathogenicity all over the world, including whether diagnostic reagents can sensitively detect new variant strains, and the effect of existing vaccines on the prevention of infection, severe illness and death of new variant strains. On the other hand, adhere to normal prevention and control measures, including the "four early" measures of early detection, early report, early isolation and early treatment. For ordinary people, it is to do a good job in vaccination and adhere to the implementation of personal protective measures, such as wearing masks, paying attention to hand hygiene and maintaining social distance. According to the situation and characteristics of this round of national epidemic, in the next epidemic prevention and control, Wu Zunyou also reminded all localities to recognize the following four aspects: 1、 We should be prepared ideologically for a long-term struggle with the new crown We need to strengthen our confidence in overcoming the epidemic, but we should not be blinded by the overly optimistic message of the end of the epidemic. 2、 We should improve the ability of epidemic prevention and control Especially for COVID-19, which is likely to be large-scale, it has the ability to anticipate and to avoid large-scale epidemic. 3、 We should further strengthen the vaccination of Xinguan vaccine Especially for the elderly and people with basic diseases. Vaccination is the basic work of Xinguan prevention and control. Four, prepare to meet the scale of COVID-19 that may happen. Including personnel guarantee; Have the ability to complete the nucleic acid detection of all personnel involved in the epidemic within the jurisdiction in a short, frequent and fast manner; Expand medical facilities to ensure that they can meet the demand for medical services caused by the surge in the number of infected people in a short period of time; Expand shelter isolation facilities to ensure that asymptomatic infected persons and mild cases can be isolated and observed; Reserve other medical treatment resources. (Xinhua News Agency)