What is the prevalence of the Omicron variant?

What is the prevalence of the Omicron variant? How about communication? In the face of the new variant of COVID-19, what should the public pay attention to in their daily work? See the National Health Commission’s answer for details

Q:What is the discovery and prevalence of Omicron variants?
A:In November 9, 2021, a variant of COVID-19 B.1.1.529 was detected for the first time in South Africa. 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, who defined it as the fifth “variant of concern” (VOC), named the Greek letter Omicron variant. As of November 28, South Africa, Israel, Belgium, Italy, Britain, Austria and Hong Kong, China had monitored the input of the mutant. The input of the mutant has not been found in other provinces and cities in China. The Omicron mutant was first discovered and reported in South Africa, but it does not mean that the virus evolved in South Africa, and the discovery place of the mutant is not necessarily the place of origin.

Q:What are the possible reasons for the emergence of Omicron mutant?

A: According to the information shared by COVID-19 database GISAID, the number of mutation sites of COVID-19′s variant was significantly higher than that of all COVID-19 variants in recent 2 years, especially in Spike. It is speculated that there may be the following three reasons:
(1) after infection with COVID-19, the immune deficiency patients experienced a long time evolution and accumulated a large number of mutations in the body.
(2) the infection of COVID-19 in some animal group has undergone adaptive evolution in the process of animal population transmission, with mutation rate higher than that of human beings, and then spilling over to humans.
(3) the mutation 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.

Q:What is the transmissibility of the Omicron variant?
A: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 mutation sites that enhance cell receptor affinity and virus replication ability. Epidemiological and laboratory surveillance data show that the number of cases infected with Omicron mutant in South Africa has increased sharply and partially replaced delta mutant. The transmission ability needs further monitoring and research.

Q:How does the Omicron variant affect vaccines and antibody drugs?
A:Studies show that if K417N, E484A or N501Y mutations occur in COVID-19 S 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, and the immune escape ability of existing vaccines needs to be further monitored and studied.

Q:Does Omicron mutant affect the nucleic acid detection reagents currently used in China?
A:Genomic analysis of Omicron mutant showed that its mutation site did not affect the sensitivity and specificity of mainstream nucleic acid detection reagents in China. The mutation sites of the mutation were mainly concentrated in the high variation region of S protein gene, not located in the primer and probe target area of the nucleic acid detection reagent released in the 8th edition of New Coronavirus pneumonia prevention and control program (the ORF1ab gene and N gene released by China CDC virus disease to the world). However, the data from several laboratories in South Africa suggest that the nucleic acid detection reagent with the detection target of S gene may not be able to effectively detect the S gene of Omicron mutant.

Q:What are the measures taken by relevant countries and regions?
A: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, Taiwan and Hong Kong, have restricted the entry of tourists from southern Africa.

Q:What are China’s countermeasures?
A:The prevention and control strategy of “external defense input and internal defense rebound” in China is still effective for Omicron 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 Omicron mutant, and continues to carry out virus genome monitoring for possible input cases. The above measures will be conducive to the timely detection of Omicron mutants that may be imported into China.

Q:What are the recommendations of who to deal with the Omicron variant?
A: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.

Q:In the face of the new variant of COVID-19, what should the public pay attention to in their daily work?
A:(1) Wearing a mask is still an effective way to block the transmission of the virus, and it is also applicable to the Omicron variant. Even if the whole process of vaccination and booster injection have been completed, it is also necessary to wear masks in indoor public places, public transport and other places. In addition, wash hands frequently and do a good job in indoor ventilation. (2) Do a good job in personal health monitoring. In case of suspected novel coronavirus pneumonia symptoms such as fever, cough, shortness of breath, etc., timely monitoring of body temperature and active treatment. (3) Reduce unnecessary entry and exit. In just a few days, many countries and regions have successively reported the import of Omicron mutant. China is also facing the risk of the import of this mutant, and the global understanding of this mutant is still limited. Therefore, travel to high-risk areas should be minimized, personal protection during travel should be strengthened, and the chance of infection with Omicron mutant should be reduced