Knowledge and prevention of COVID-19's variant of the Olympic Games —— Relevant experts from the PLA Center for Disease Control and prevention answered reporters' questions ■ Chen Yong, Zheng Longqing, PLA Daily reporter Sun Xingwei Recently, South Africa and other places found a new variant of COVID-19, COVID-19. It was listed as a variant strain of "need attention" by WHO in November 26th. What are the characteristics of Omicron mutant? What are the risks? In view of the current severe and complex situation of epidemic prevention and control, how should we do a good job in normalized prevention and control? In this regard, the reporter interviewed relevant experts from the PLA Center for Disease Control and prevention. Reporter: how about the discovery and prevalence of Omicron mutant? Experts: in November 9, 2021, South Africa first detected a new variant of COVID-19, B.1., from the case samples. 1.529。 In just two weeks, the mutant became the absolute dominant mutant of new crown infection cases in Gauteng Province, South Africa, with rapid growth. On November 26, the World Health Organization defined it as the fifth "concern variant", named Omicron (Omicron) variant. As of December 2nd, the input of the mutant strain has been monitored in more than 20 countries, including South Africa, Botswana, Israel, Belgium, Italy, Britain, Austria, Brazil, the United States, Japan and China. The Omicron mutant was first found in South Africa, but it does not mean that the virus evolved in South Africa. The discovery place of the mutant is not necessarily the place of origin. The World Health Organization identified the Omicron variant as a "concern" variant, which means that the World Health Organization believes that it may have higher transmission power, or increase the risk of severe illness, or reduce the effectiveness of current diagnosis, vaccines and therapies. Reporter: what are the possible reasons for the emergence of Omicron mutant? Expert: according to the information currently shared by COVID-19's open database website GISAID, the number of mutation sites of COVID-19's variant is significantly higher than that of all COVID-19 variants prevalent in recent 2 years, especially in the Spike mutation. It is speculated that the reasons may be in 3 cases: first, the infected patients infected with COVID-19, after a long time of evolution, accumulated a large number of mutations, and then began to spread. Two, COVID-19 is infected by some animal group. The virus adaptate in the process of animal population transmission, and the mutation rate is higher than that of human beings, and then spills over to humans. Three, the mutant has been in the COVID-19 genome for a long time in the backward countries or regions. Due to the lack of monitoring ability, the evolution of the intermediate generation virus can not be detected in time. Reporter: what is the transmission power of Omicron mutant? Expert: at present, there is no systematic research data on the transmissibility, pathogenicity and immune escape ability of Omicron mutant in the world. However, Omicron mutant also has important amino acid mutation sites of alpha (alpha), beta (beta), gamma (gamma) and delta (delta) spike proteins of the first four VOC mutants, including some mutation sites that have been found in previous studies to enhance cell receptor affinity and virus replication ability. Epidemiological and laboratory monitoring data show that the number of cases infected with Omicron mutant in South Africa has increased significantly and partially replaced delta mutant, suggesting that Omicron mutant may also have strong transmission power, but whether it has competitive advantage compared with delta remains to be further monitored and studied. Reporter: what are the effects of Omicron mutant on the effects of existing vaccines and antibody drugs? Expert: studies show that if K417N, E484A or N501Y mutation occurs in COVID-19 spike protein, the immune escape ability will be enhanced. There was a triple mutation of "k417n + e484a + n501y" in Omicron mutant; In addition, there are many other mutations that may reduce the neutralizing activity of some monoclonal antibodies. The superposition of mutations may reduce the protective effect of some antibody drugs on Omicron mutant, but its immune escape ability to the existing vaccine needs further monitoring and laboratory research. Reporter: does the Omicron mutant have an impact on the nucleic acid detection reagents currently used in China? Expert: the genomic analysis of Omicron mutant shows that its mutation site does not affect the sensitivity and specificity of China's mainstream nucleic acid detection reagents. The mutation sites of the mutation were mainly concentrated in the high variation region of the S protein gene, not located in the primer and probe target region (ORF1ab gene and N gene) of nucleic acid detection reagent published in the 8th edition of New Coronavirus pneumonia prevention and control program. However, the data from several laboratories in South Africa suggest that the S-based nucleic acid detection reagent for detecting the target may not be able to effectively detect the S gene of Omicron mutant. Reporter: what are the measures taken by relevant countries and regions? Expert: in view of the rapid epidemic trend of Omicron mutant in South Africa, many countries and regions, including the United States, the United Kingdom, the European Union, Russia, Israel, Japan, Taiwan and Hong Kong, have restricted the entry of tourists from South Africa or other regions. Reporter: what are China's response measures? Expert: China's "external defense input and internal defense rebound" prevention and control strategy is still effective for Omicron mutant. China Center for Disease Control and prevention has established a specific nucleic acid detection method for Omicron mutant, and continued to carry out virus genome monitoring for input cases. The above measures will be conducive to the timely detection of Omicron mutants that may be imported into China. Reporter: what are the recommendations of the World Health Organization to deal with the Omicron variant? Expert: WHO recommends that all countries strengthen COVID-19's monitoring, reporting and research, and take effective public health measures to stop virus transmission. It is recommended that individuals take effective infection prevention measures, including maintaining a distance of at least 1m in public places, wearing masks, opening windows for ventilation, keeping hands clean, coughing or sneezing at elbows or paper towels, vaccination, etc., and avoiding going to poorly ventilated or crowded places. Compared with other VOC mutants, it is uncertain whether the transmissibility, pathogenicity and immune escape ability of Omicron mutants are stronger. Preliminary results will be obtained in the next few weeks. However, it is known that all variants may lead to severe illness or death, so preventing virus transmission is always the key. The new crown vaccine is still effective in reducing severe illness and death. Reporter: in the face of the new variant of COVID-19, what do officers and soldiers need to pay attention to in their work and life? Novel coronavirus pneumonia: experts: in the past two years, we have accumulated a set of effective prevention and control experience in the prevention and control of the new crown pneumonia epidemic. At present, the normalization prevention and control measures taken by the army are also applicable to the Omicron mutant. Wearing a mask is an effective way to block the spread of the virus. Even if the whole process of vaccination and vaccination booster needle have been completed, it is also necessary to wear a mask in indoor public places and public transport. In addition, wash hands frequently, reduce aggregation, implement personal health monitoring and do a good job in indoor ventilation; In case of suspected novel coronavirus pneumonia symptoms such as fever, cough, shortness of breath, etc., report and consult in time. (outlook new era)