Reporter : Li Ming
Editor : Ming Xuan
Publisher : New Tang Dynasty Television
Translation, editing : Gan Yung Chyan
/ KUCINTA SETIA
Image : The picture shows a person wearing protective clothing and a protective mask in Beijing, China, spraying disinfectant on a public place in a residential area on 21 June 2020 to prevent the spread of SARS-CoV-2 in the residential area. (Kevin Frayer/Getty Images)
The official anti-epidemic agency of the Communist Party of China has recently released the three sets of genomic sequence data of the first batch of virus samples (SARS-CoV-2 / CCP virus) from the new epidemic in Beijing. Medical experts found through data alignment that these sequences all carry the D614G mutation. The research results of European and American experts show that the D614G mutation can significantly enhance the infectivity of the virus, and the highest degree of enhancement can be up to 9 times.
In the evening of 18 June 2020, the Chinese Center for Disease Control and Prevvention (China CDC) uploaded the genome sequence data of the three strains of SARS-CoV-2 as obtained from Xinfadi Market in early June this year to the Global Shared Influenza Data Initiative database (GISAID). All three reported virus samples were collected on 11 June and they came from newly diagnosed cases and environmental samples.
A report from the Chinese media Caixin.com quoted an expert from the China CDC as saying that the research confirmed that the genetic evolution lineages of these viruses belong to the European evolutionary branch, but the specific source of the virus has yet to be investigated. Medical experts have studied these three sets of viral genome sequence data and found that these viruses all have D614G mutation.
The report said that researchers analyzed the nucleic acid sequence of 4535 novel coronaviruses in the GISAID database and found that the D614G mutant strain began to spread widely in Europe in early February, and after entering other regions, it quickly became the main local strain type, and its proportion continued to increase. The increase has gradually become the mainstream strain of the world. Researchers estimate that the proportion of D614G strains in all CCP viruses was 26% in March, rose to 65% in April, and its share had reached 70% in May.
The researchers pointed out that the D614G mutation may double the infectivity of the virus, and may also increase the patient's viral load and risk of death. Several groups of research teams have confirmed through pseudovirus experiments that the mutant strain with the D614G mutation has more than the old strain. Strong contagion.
According to reports, a research paper published by the Hyeryun Choe team of the Scripps Research Institute in the preprint website bioRxiv on the 12th of this month said that in the hACE2-293T cell line expressing ACE2 human embryonic kidney cells, The infection capacity of pseudovirus with D614G mutation in S protein increased about 9 times.
In addition, the research team of Neville E. Sanjana of the New York Genome Research Center also published in bioRxiv that based on cell lines such as pseudoviruses and human lung epithelial cells, it was found that the D614G mutation increased the ability of pseudoviruses to infect cells 2.4 -7.7 times, of which the efficiency of infecting human hepatocytes (Huh7.5-ACE2) is the most significant.
The researchers also pointed out that the D614G mutation makes the S protein more stable during production and virus assembly, resulting in a larger number of fully functional S proteins on the surface of the virus, resulting in a significant increase in the ability of this virus to infect.
However, the aforementioned two studies have not been formally published without peer review, so more clinical data are needed to verify the characteristics of the virus after the D614G mutation.
Some netizens believe that since the new strain of the outbreak in Beijing belongs to the D614G mutant strain, it means that the outbreak in Beijing is more difficult to control than the outbreak in Wuhan. A few days ago, officials of the China CDC claimed that the epidemic in Beijing had been brought under control, and now it seems to be wishful thinking.
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