Last November, the researchers found that a patient in the Kanto region, which encompasses Tokyo, had a strain called "20C," which has mainly been spreading on the US West Coast.
The patient had not traveled abroad, which suggests the virus was community-acquired.
The current outbreak in Japan mainly consists of two types of the coronavirus that remained after the first wave last year. The 20C strain has not been detected since May last year, except at quarantine stations.作者: kw_lam 時間: 2021-1-14 09:17 PM
Genomic virus surveillance can lead to early identification of new variants and inform proper response during a pandemic. Using this approach, we have identified a new variant of the SARS-CoV-2 virus that emerged in the United States (U.S.) early in the coronavirus disease (COVID-19) pandemic and has become one of the most prevalent U.S variants. This new variant within the B.1.2 lineage referred to here as 20C-US, has not yet spread widely to other countries. The earliest 20C-US genomes can be traced to the southern U.S. in late May of 2020. A major early event was the rapid acquisition of five non-synonymous mutations. The changes carried by 20C-US now include mutations to genes involved in virus particle maturation and release, processing of viral proteins, and RNA genome integrity and translation genes, all important for efficient and accurate virus production. In addition, 20C-US has since acquired two new non-synonymous mutations that highlight its ongoing evolution, one of which is a Q677H mutation in the spike protein adjacent to the furin cleavage site. We predict that 20C-US may already be the most dominant variant of SARS-CoV-2 in the U.S. The ongoing evolution of 20C-US, as well as other dominant region-specific variants emerging around the world, should continue to be monitored with genomic, epidemiologic, and experimental studies to understand viral evolution and predict future outcomes of the pandemic.作者: kw_lam 時間: 2021-1-14 09:19 PM
Ralph Baric 一名美國北卡羅來納州大學有2015年11月9日刊登他們團隊，製做一種擁有SCH014表面蛋白質冠狀病毒的研究。
Lab-Made Coronavirus Triggers Debate
The creation of a chimeric SARS-like virus has scientists discussing the risks of gain-of-function research.
Nov 16, 2015
Ralph Baric, an infectious-disease researcher at the University of North Carolina at Chapel Hill, last week (November 9) published a study on his team’s efforts to engineer a virus with the surface protein of the SHC014 coronavirus, found in horseshoe bats in China, and the backbone of one that causes human-like severe acute respiratory syndrome (SARS) in mice. The hybrid virus could infect human airway cells and caused disease in mice, according to the team’s results, which were published in Nature Medicine.
The results demonstrate the ability of the SHC014 surface protein to bind and infect human cells, validating concerns that this virus—or other coronaviruses found in bat species—may be capable of making the leap to people without first evolving in an intermediate host, Nature reported. They also reignite a debate about whether that information justifies the risk of such work, known as gain-of-function research. “If the [new] virus escaped, nobody could predict the trajectory,” Simon Wain-Hobson, a virologist at the Pasteur Institute in Paris, told Nature.
In October 2013, the US government put a stop to all federal funding for gain-of-function studies, with particular concern rising about influenza, SARS, and Middle East respiratory syndrome (MERS). “NIH [National Institutes of Health] has funded such studies because they help define the fundamental nature of human-pathogen interactions, enable the assessment of the pandemic potential of emerging infectious agents, and inform public health and preparedness efforts,” NIH Director Francis Collins said in a statement at the time. “These studies, however, also entail biosafety and biosecurity risks, which need to be understood better.”
Baric’s study on the SHC014-chimeric coronavirus began before the moratorium was announced, and the NIH allowed it to proceed during a review process, which eventually led to the conclusion that the work did not fall under the new restrictions, Baric told Nature. But some researchers, like Wain-Hobson, disagree with that decision.
The debate comes down to how informative the results are. “The only impact of this work is the creation, in a lab, of a new, non-natural risk,” Richard Ebright, a molecular biologist and biodefence expert at Rutgers University, told Nature.
But Baric and others argued the study’s importance. “[The results] move this virus from a candidate emerging pathogen to a clear and present danger,” Peter Daszak, president of the EcoHealth Alliance, which samples viruses from animals and people in emerging-diseases hotspots across the globe, told Nature.