However, cluster infections started to occur across the country from mid-June onwards.
A genetic analysis of virus samples taken from these clusters found they were mutated versions of the European strAIn.
该病毒株命名为hCoV-19/Japan/Hu_KngFJ_23RD5/2020。 信息熵,是在6月份采集,7月30日上传,符合此次日本病毒株流行的时间线。上传机构为Takayuki Hishiki Kanagawa Prefectural Institute of Public Health。 ————该病毒序列是否发生了变异?————
新闻上提到了病毒株发生变异,因此我们接下来就来分析该病毒株的序列信息。
相比于武汉上传的参考病毒序列,这条新序列多了24bp的插入(插入就是多了,说明基因发生了变化)。 Insertion of 24 nucleotides when compared to the reference sequence.
当然,这很正常,病毒从武汉上传之后,就发生了许多变异,在全世界形成了数百个病毒株,那这条序列的变异如何?
该序列上有11个SNP,1个insertion,1个deletion 病毒属于欧洲型D614G
首先看SNP,果然发现了熟悉的D614G(QHD43416.1:p.614D>G)
事实上,对于D614G的感染能力变强,已经有多个相应的实验证据来佐证了。
来自佛罗里达州Scripps Research Institute的研究人员用新冠病毒关键蛋白S蛋白构建了D614和G614的伪病毒并用来感染人肾上皮细胞系293T,然后检测感染后细胞中的荧光变化,发现变异后的G614感染细胞能力明显提高,如下图中的所示,G614感染细胞能力要高出D614一个数量级[3]。
(说明,上图是检测的循环要求,越低表明病毒载量越高,可以看到G614患者病毒载量更高)。
上述研究都佐证了一个事实:D614G属于感染性更强的病毒株。
1 Sanche S, Lin Y T, Xu C, et al. High Contagiousness and Rapid Spread of Severe Acute Respiratory Syndrome Coronavirus 2[J]. Emerging Infectious Diseases, 2020, 26(7).
2 Spike mutation pipeline reveals the emergence of a more transmissible form of SARS-CoV-2
3 Lizhou Zhang et.al,The D614G mutation in the SARS-CoV-2 spike protein reduces S1 shedding and increases infectivity
4 Zharko Daniloski et.al,The D614G mutation in SARS-CoV-2 Spike increases transduction of multiple human cell types
补充说明:本内容分析由个人完成,受制于病毒株上传信息以及个人分析能力限制,因此不能保证正确性,本文仅供参考。 由于目前信息非常少,且日本方面并没有最新的研究论文,因此,以下内容悬而未决 1,该病毒株是否感染性更强?还是仅仅是因为人群放松警惕而导致的扩散? 2,该病毒株是否致病性更强?目前确诊人数攀升,死亡人数和重症人数也在攀升,但比率并未有攀升,这要取决于最终的总人数,因为病毒感染到发病要有一个周期。 3,D614G及此次日本的变异株,是否会影响疫苗有效性?全球人都想知道,科研工作者也不例外,但是截至目前:未知~
不过,前期有一个研究,就是重医发了一篇研究,用康复病人的血浆抗体的中和实验。发现大部分情况下,康复者的抗体可以中和感染者,但也存在部分患者没有效果,这意味着,即便是来自标准病毒的抗体,也不能起到100%的效果,意味着D614G改变了S蛋白的免疫原性。以此推测,疫苗效果不一定有那么好。
However, cluster infections started to occur across the country from mid-June onwards.
A genetic analysis of virus samples taken from these clusters found they were mutated versions of the European strain.
该病毒株命名为hCoV-19/Japan/Hu_KngFJ_23RD5/2020。 信息熵,是在6月份采集,7月30日上传,符合此次日本病毒株流行的时间线。上传机构为Takayuki Hishiki Kanagawa Prefectural Institute of Public Health。 ————该病毒序列是否发生了变异?————
新闻上提到了病毒株发生变异,因此我们接下来就来分析该病毒株的序列信息。
相比于武汉上传的参考病毒序列,这条新序列多了24bp的插入(插入就是多了,说明基因发生了变化)。 Insertion of 24 nucleotides when compared to the reference sequence.
当然,这很正常,病毒从武汉上传之后,就发生了许多变异,在全世界形成了数百个病毒株,那这条序列的变异如何?
该序列上有11个SNP,1个insertion,1个deletion 病毒属于欧洲型D614G
首先看SNP,果然发现了熟悉的D614G(QHD43416.1:p.614D>G)
事实上,对于D614G的感染能力变强,已经有多个相应的实验证据来佐证了。
来自佛罗里达州Scripps Research Institute的研究人员用新冠病毒关键蛋白S蛋白构建了D614和G614的伪病毒并用来感染人肾上皮细胞系293T,然后检测感染后细胞中的荧光变化,发现变异后的G614感染细胞能力明显提高,如下图中的所示,G614感染细胞能力要高出D614一个数量级[3]。
(说明,上图是检测的循环要求,越低表明病毒载量越高,可以看到G614患者病毒载量更高)。
上述研究都佐证了一个事实:D614G属于感染性更强的病毒株。
1 Sanche S, Lin Y T, Xu C, et al. High Contagiousness and Rapid Spread of Severe Acute Respiratory Syndrome Coronavirus 2[J]. Emerging Infectious Diseases, 2020, 26(7).
2 Spike mutation pipeline reveals the emergence of a more transmissible form of SARS-CoV-2
3 Lizhou Zhang et.al,The D614G mutation in the SARS-CoV-2 spike protein reduces S1 shedding and increases infectivity
4 Zharko Daniloski et.al,The D614G mutation in SARS-CoV-2 Spike increases transduction of multiple human cell types
补充说明:本内容分析由个人完成,受制于病毒株上传信息以及个人分析能力限制,因此不能保证正确性,本文仅供参考。 由于目前信息非常少,且日本方面并没有最新的研究论文,因此,以下内容悬而未决 1,该病毒株是否感染性更强?还是仅仅是因为人群放松警惕而导致的扩散? 2,该病毒株是否致病性更强?目前确诊人数攀升,死亡人数和重症人数也在攀升,但比率并未有攀升,这要取决于最终的总人数,因为病毒感染到发病要有一个周期。 3,D614G及此次日本的变异株,是否会影响疫苗有效性?全球人都想知道,科研工作者也不例外,但是截至目前:未知~
不过,前期有一个研究,就是重医发了一篇研究,用康复病人的血浆抗体的中和实验。发现大部分情况下,康复者的抗体可以中和感染者,但也存在部分患者没有效果,这意味着,即便是来自标准病毒的抗体,也不能起到100%的效果,意味着D614G改变了S蛋白的免疫原性。以此推测,疫苗效果不一定有那么好。
The National Institute of Infectious Diseases has said in a study that the coronavirus may have continued to spread unnoticed through carriers with mild or no symptoms after the outbreak from March to April receded once.
The recently released study suggested that such a phenomenon may have led to the resurgence of COVID-19 infections in and after June, when Japan began resuming economic activities.
In the study, which ran through July 16, the institute collected coronavirus samples from some 3,700 patients and analyzed the genome sequence.
Because a virus undergoes mutations during the course of infection, the institute deduced how COVID-19 spread by looking at how the virus changed. The genome analysis found that the so-called European type of the virus spread widely in Japan in and after March but waned in late May thanks to preventive measures.
In mid-June, however, an apparent variant of the European type was found in Tokyo that is believed to have emerged after more than three months of mutations. And a virus derived from that variant was later found in many other parts of Japan.
As the institute did not find any virus that was in the midst of the mutation process, it pointed to the possibility that the coronavirus quietly spread among younger carriers, who tend to show no or little symptoms, and thus went unnoticed by public health centers.
In the report, the institute noted that the coronavirus apparently could not be contained within Tokyo and eventually spread across the country, partly because people started making business trips after the economy reopened.[1]