Recently, news about the Omikron variant has been on the hot search several times. On the evening of November 29, the National Center for Disease Control and Prevention proposed the following nine things for the new crown Omikron variant!

1. Discovery and prevalence of Omicron variants

     On November 9, 2021, South Africa detected a new coronavirus B.1.1.529 variant strain for the first time from case samples. In just 2 weeks, this variant has become the absolute dominant variant of new crown infection cases in Gauteng, South Africa, with rapid growth.

     On November 26, WHO defined it as the fifth "variant of concern" (VOC), named after the Greek letter Omicron (Omicron) variant. As of November 28, South Africa, Israel, Belgium, Italy, the United Kingdom, Austria and Hong Kong, China, etc., have monitored the input of this variant. The importation of this variant has not been found in other provinces and cities in my country. The Omicron variant was first discovered and reported in South Africa, but it does not mean that the virus evolved in South Africa, and the place where the variant was found is not necessarily the place of origin.

2. Possible reasons for the emergence of Omicron mutants

     According to the information currently shared by the new coronavirus database GISAID, the number of mutation sites of the new coronavirus Omicron variant is significantly more than that of all the new coronavirus variants that have been circulating in the past two years, especially in the virus spike (Spike) protein has more mutations. . It is speculated that there may be the following three reasons:

(1) After immunocompromised patients are infected with the new coronavirus, they have undergone a long period of evolution in the body and accumulated a large number of mutations, which are transmitted by chance;

(2) When a certain animal group is infected with the new coronavirus, the virus undergoes adaptive evolution during the transmission of the animal group, and the mutation rate is higher than that of humans, and then spills over to humans;

(3) The variant strain has been circulating for a long time in countries or regions where the monitoring of new coronavirus genome variation is backward. Due to insufficient monitoring capabilities, the intermediate generation of its evolution has not been discovered in time.

3. Transmissibility of Ormicron Variants

     At present, there is no systematic research data on the transmissibility, pathogenicity and immune evasion ability of Ormicron mutants in the world. However, the Omicron variant also has important amino acid mutation sites in the spike proteins of the first four VOC variants, Alpha (alpha), Beta (beta), Gamma (gamma) and Delta (delta), including enhanced cellular Mutation sites for somatic affinity and viral replication ability. Epidemiological and laboratory surveillance data show that the number of cases infected with the Omicron variant in South Africa has increased significantly, and it has partially replaced the Delta (delta) variant. The transmission capacity needs to be further monitored and studied.

4. The effect of Omicron variant strains on vaccines and antibody drugs

     Studies have shown that if K417N, E484A or N501Y mutations appear in the S protein of the new coronavirus, it indicates that the immune escape ability is enhanced; while the Omicron variant also has a triple mutation of "K417N+E484A+N501Y"; There are multiple other mutations that may reduce the neutralizing activity of some mAbs. The superposition of mutations may reduce the protective efficacy of some antibody drugs against Omicron mutants, and the ability of existing vaccines to escape immunity needs further monitoring and research.

5. Does the Omicron variant have any effect on the nucleic acid detection reagents currently used in my country

     The genome analysis of the Omicron variant showed that its mutation site did not affect the sensitivity and specificity of the mainstream nucleic acid detection reagents in my country. The mutation sites of the Omicron variant are mainly concentrated in the hypervariable region of the S protein gene, and are not located in the nucleic acid detection reagent primers and probe target regions announced in the Eighth Edition of my country's "New Coronavirus Pneumonia Prevention and Control Plan" (China ORF1ab gene and N gene announced to the world by the Center for Viral Diseases of the Centers for Disease Control and Prevention). However, data from multiple laboratories in South Africa suggest that nucleic acid detection reagents that target the S gene may not be able to effectively detect the S gene of the Omicron variant.

6. Measures taken by relevant countries and regions

     In view of the rapid prevalence of Omicron variants 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 travelers from southern Africa.

7. Our country's response

     The prevention and control strategy of "foreign defense against importation and internal defense against rebound" in my country is still effective for Omicron mutants. The Institute of Viral Diseases of the Chinese Center for Disease Control and Prevention has established a specific nucleic acid detection method for the Ormicron variant, and continues to carry out viral genome surveillance for possible imported cases. The above measures will facilitate the timely discovery of Omicron mutants that may be imported into my country.

8. WHO's recommendations for response to Omicron variants

    WHO recommends that countries strengthen the monitoring, reporting and research of the new coronavirus, and take effective public health measures to block the spread of the virus; effective infection prevention measures recommended by individuals include maintaining a distance of at least 1 meter in public places, wearing masks, opening windows for ventilation, maintaining Clean your hands, cough or sneeze into your elbow or a tissue, get vaccinated, etc., and avoid poorly ventilated or crowded places. Compared with other VOC variants, it is uncertain whether the Omicron variant is more transmissible, pathogenic, and immune to evasion, and preliminary results will be available in the next few weeks. But what is currently known is that all variants can 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 emerging new coronavirus Omicron variant, what should the public pay attention to in their daily work?

(1) Wearing a mask is still an effective way to block the spread of the virus, and it is also applicable to the Omicron variant. Even if the full course of vaccination and booster shots have been completed, it is also necessary to wear masks in indoor public places, public transportation and other places. In addition, wash your hands frequently and do good indoor ventilation.

(2) Do a good job in personal health monitoring. When there are symptoms of suspected new coronary pneumonia, such as fever, cough, shortness of breath and other symptoms, monitor the body temperature in time and take the initiative to seek medical treatment.

(3) Reduce non-essential entry and exit. In just a few days, many countries and regions have successively reported the import of the mutant strain of Omicron. my country is also facing the risk of importing the mutant strain, and the global understanding of the 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 contracting the Omicron variant.