Discovery and prevalence of Omi Keron mutant strains

1. Discovery and prevalence of Omi Keron mutant strains On November 9, 2021, South Africa detected a B.1.1.529 variant of the new coronavirus from a case sample for the first time. In just 2 weeks, the mutant strain became the absolute dominant mutant strain of the new crown infection cases in Gauteng Province, South Africa, and its growth was rapid. On November 26, the WHO defined it as the fifth “variant of concern” (VOC), named the Greek letter Omicron (Omicron) variant. As of November 28, South Africa, Israel, Belgium, Italy, the United Kingdom, Austria, and Hong Kong, China, have monitored the input of the mutant strain. The input of this mutant strain has not been found in other provinces and cities in my country. The Omi Keron mutant was first discovered and reported in South Africa, but it does not mean that the virus evolved in South Africa. The place where the mutant was found is not necessarily the place of origin.

2. Possible reasons for the emergence of Omi Keron mutants According to the information currently shared by the new crown virus database GISAID, the number of mutation sites of the new crown virus Omi Keron mutant strain is significantly more than that of all the new crown virus mutant strains that have been circulating in the past two years, especially in the virus spike (Spike) protein mutations. . It is speculated that the reasons for its emergence may be the following three situations: (1) After the immunodeficiency patient is infected with the new coronavirus, he has experienced a long period of evolution in the body to accumulate a large number of mutations, which are transmitted by chance; (2) a certain animal group infection New coronavirus, the virus undergoes adaptive evolution during the spread of animal populations, and the mutation rate is higher than that of humans, and then spills into humans; (3) This mutant strain has continued to circulate for a long time in countries or regions where the mutation monitoring of the new coronavirus genome is lagging. , Due to insufficient monitoring capabilities, the intermediate generation viruses of its evolution could not be detected in time.

3. Transmission ability of Omi Keron mutant strain At present, there is no systematic research data on the transmission, pathogenicity, and immune escape ability of Omi Keron mutants in the world. However, the Omi Keron variant also has important amino acid mutation sites in the first four VOC variants Alpha, Beta, Gamma and Delta spike proteins, including enhanced cell receptors. Mutation sites for somatic affinity and virus replication ability. Epidemiological and laboratory monitoring data show that the number of cases of Omi Keron variants in South Africa has increased significantly, and has partially replaced the Delta (Delta) variants. The transmission capacity needs to be further monitored and studied.

4. The impact of Omi Keron variant strain on vaccines and antibody drugs Studies have shown that the presence of K417N, E484A, or N501Y mutations in the S protein of the new coronavirus indicates an enhanced immune escape ability; while the Omi Keron mutant also has a triple mutation of “K417N+E484A+N501Y”; in addition, the Omi Keron mutant also There are many other mutations that may reduce the neutralizing activity of some monoclonal antibodies. The superposition of mutations may reduce the protective efficacy of some antibody drugs against Omi Keron mutants, and the ability of existing vaccines to escape immunity needs further monitoring and research.

5. Does the Omi Keron variant affect the nucleic acid detection reagents currently used in my country? The genome analysis of the Omi Keron mutant strain showed that its mutation site does not affect the sensitivity and specificity of mainstream nucleic acid detection reagents in my country. The mutation sites of the Omi Keron mutant strain are mainly concentrated in the highly variable region of the S protein gene, and are not located in the nucleic acid detection reagent primers and probe target regions published in the eighth edition of my country’s “New Coronavirus Pneumonia Prevention and Control Program” (China The ORF1ab gene and N gene released by the Centers for Disease Control and Prevention to the world). However, data from multiple laboratories in South Africa suggests that nucleic acid detection reagents that detect the S gene may not be able to effectively detect the S gene of the Omi Keron variant.

6. Measures taken by relevant countries and regions In view of the rapid epidemic trend of Omi Keron mutants in South Africa, many countries and regions, including the United States, the United Kingdom, the European Union, Russia, Israel, my country’s Taiwan and Hong Kong, have restricted the entry of travelers from southern Africa.

7. my country’s response measures Our country’s prevention and control strategy of “external defense, internal defense against rebound” is still effective against the Omi Keron mutant. The Institute of Viral Diseases of the Chinese Center for Disease Control and Prevention has established a specific nucleic acid detection method for the Omi Keron mutant strain, and continues to carry out viral genome monitoring for possible imported cases. The above-mentioned measures will facilitate timely detection of Omi Keron mutants that may be imported into my country.

8. WHO’s recommendations for response to Omi Keron mutant strains The WHO recommends that countries strengthen the surveillance, reporting and research of the new coronavirus, and take effective public health measures to stop the spread of the virus; effective infection prevention measures recommended for individuals include keeping a distance of at least 1 meter in public places, wearing masks, opening windows for ventilation, and keeping Clean your hands, cough or sneeze into your elbow or tissue, get vaccinated, etc., and avoid going to poorly ventilated or crowded places. Compared with other VOC variants, it is still uncertain whether the Omi Keron variant has stronger transmission, pathogenicity and immune escape ability. The relevant research will get preliminary results in the next few weeks. But what is currently known is that all mutant strains may cause severe illness or death, so preventing the spread of the virus is always the key, and the new crown vaccine is still effective in reducing severe illness and death.

9. In the face of the newly emerged variant of the new coronavirus Omi Keron, what should the public pay attention to in their daily work and work? (1) Wearing a mask is still an effective way to block the spread of the virus, and it is also applicable to Omi Keron mutant strains. Even if the whole course of vaccination and booster vaccination has been completed, it is also necessary to wear a mask in indoor public places, public transportation and other places. In addition, wash your hands frequently and ventilate the room. (2) Do a good job of personal health monitoring. When there are symptoms of suspected new coronary pneumonia, such as fever, cough, shortness of breath and other symptoms, promptly monitor body temperature and take the initiative to see a doctor. (3) Reduce unnecessary entry and exit. In just a few days, many countries and regions have successively reported the import of Omi Keron mutant strains. China also faces the risk of importing this mutant strain, and the current global knowledge of this mutant strain is still limited. Therefore, travel to high-risk areas should be minimized, and personal protection during travel should be strengthened to reduce the chance of infection with Omi Keron mutant strains.