04 科学家对英国新冠病毒新变种表示担忧

科学家称，新毒株有两方面值得关注：一是其发生的突变数量之大前所未有，二是该变种在英格兰东南部取代新冠病毒其他毒株的速度。

全文共 917 个词，by Clive Cookson

The highly infectious variant of coronavirus that has emerged in south-east England is spreading rapidly to the rest of the UK and is already present elsewhere in the world, scientists warned on Sunday.

科学家们周日警告称，英格兰东南部出现的传染性很强的新冠病毒变种正迅速传播到英国其他地区，并已在全球其他地区出现。

The World Health Organisation said its Evolution Working Group is working closely with the UK medical authorities to understand how the variant, now called B.1.1.7, is likely to affect the course of the pandemic. It has been detected in the Netherlands, Denmark and Australia.

世界卫生组织（WHO）称，其新冠病毒进化工作组（SARS-CoV-2 Evolution Working Group）正与英国医疗当局密切合作，以了解这种目前被称为B.1.1.7 的变种可能会如何影响疫情发展。该变种已在荷兰、丹麦和澳大利亚被检测出。

Scientists say two aspects of B.1.1.7 give cause for concern. One is the unprecedented number of mutations it carries. The other is the speed with which it is supplanting other strains of the Sars-Cov-2 virus in south-east England.

科学家们称B.1.1.7 有两方面值得关注。一是其发生的突变数量之大前所未有。二是该变种在英格兰东南部取代SARS-CoV-2 其他毒株的速度。

Jeffrey Barrett, director of the Covid Genomics Initiative at the Wellcome Sanger Institute, said 23 letters in the viral genetic code had changed, of which 17 might affect the behaviour of the virus — in particular helping it to enter and propagate within human cells.

英国惠康桑格研究所（Wellcome Sanger Institute） COVID基因组项目（COVID Genomics Initiative）负责人杰弗里·巴雷特（Jeffrey Barrett）表示，新冠病毒遗传密码中有 23 个字母发生了变化，其中 17 个可能会影响该病毒的行为——尤其是帮助该病毒进入并在人体细胞内繁殖。

“This new variant is very concerning, and is unlike anything we have seen so far in the pandemic,” he said.

他表示：“这一新变种非常令人担忧，它不像我们之前在这场大流行中见过的任何变种。”

There is no evidence so far that the mutations are affecting the course of the illness in people who are infected with B.1.1.7 or the effectiveness of Covid-19 vaccines under development.

到目前为止，还没有证据表明这些突变正在影响B.1.1.7 感染者的病程或正在研发的新冠肺炎（COVID-19，即 2019 冠状病毒病）疫苗的有效性。

“Hospitalisation rates have gone up recently [in south-east England] but roughly in line with the increase in case numbers, which doesn’t point to the new strain leading to more severe symptoms” said François Balloux, director of the UCL Genetics Institute in London.

伦敦大学学院遗传学研究所（UCL Genetics Institute）所长弗朗索瓦·巴卢（François Balloux）表示：“最近（在英格兰东南部）住院率上升了，但与病例数的增加大致相符，这似乎表明新的毒株不会导致更严重的症状。”

“I’d be very surprised if any evidence arose that it creates more serious symptoms,” Prof Balloux added. “It’s also not a strain that should be able to escape protection provided by immunisation caused by the current vaccines or prior infection.”

“如果有证据表明它会引起更严重的症状，我会非常惊讶。”巴卢补充道。“它也应该不是一种能躲避由当前疫苗或先前感染引发的免疫力的毒株。”

But Kristian Andersen, director of infectious disease genomics at Scripps Research Institute in California, said: “I have seen many articles stating ‘no effect on immunity or vaccines or clinical features. That is not correct... The fact is we don’t know but we will in coming weeks.”

但加州斯克利普斯研究所（Scripps Research Institute）传染病基因组学负责人克里斯蒂安·安德森（Kristian Andersen）表示：“我看过很多文章说‘对免疫力、疫苗或临床表现没有影响’。那并不准确……事实是我们不了解，但我们会在未来几周了解。”

Scientists at the UK government’s Porton Down microbiology labs and elsewhere are working hard to understand whether and if so how the mutations affect the severity of disease and the body’s immune response as well as viral transmissibility.

英国政府的波顿唐（Porton Down）微生物学实验室及其他地方的科学家们正在努力了解，这些突变会否——以及如何——影响病情的严重程度和人体的免疫反应，以及病毒的传染性。

The increased infectivity of the variant is illustrated by the fact that, after appearing in Kent on September 20, it was responsible for 28 per cent of infections in London by early November and 62 per cent in the week ending December 9.

表明该变种增强传染性的一个事实是：自 9 月 20 日在肯特郡（Kent）出现后，到 11 月初，该变种在伦敦造成了 28%的感染；在 12 月 9 日结束的那一周造成 62%的感染。

Computer modelling suggests that it is 70 per cent more transmissible than other Sars-Cov-2 strains circulating in the UK and raises the R value — the average number of people to whom someone with Covid-19 passes the infection — by 0.4, which makes the pandemic far harder to control without stringent lockdown measures.

计算机建模似乎表明，该变种的传染性比在英国传播的其他SARS-CoV-2 毒株高出 70%，并将R值——每一位新冠感染者进而感染的平均人数——推高 0.4，这意味着如果不采取严格的封锁措施，疫情将更加难以控制。

According to a paper released on Saturday by the Covid-19 Genomics Consortium UK, labs have sequenced 1,623 Sars-Cov-2 viral genomes showing the B.1.1.7 variant. These include 519 in London, 555 in Kent, 545 elsewhere in the UK including Scotland and Wales, and four in other countries.

英国COVID-19 基因组学联盟（COVID-19 Genomics Consortium UK）上周六发表的一篇论文显示，各实验室已对 1623 例显示出B.1.1.7 变种的SARS-CoV-2 病毒进行基因组测序。其中包括伦敦的 519 例，肯特郡的 555 例，苏格兰和威尔士等英国其他地区的 545 例，以及其他国家的 4 例。

Regular Covid-19 tests do not detect viral mutations. Variants can only be identified through a readout of all 30,000 letters of genetic code in each Sars-Cov-2 sample using specialised sequencing machines.

常规的新冠检测不检测病毒突变。只有使用专门的测序仪器读出每例SARS-CoV-2 样本遗传密码的全部 3 万个字母，才能识别变种。

“The UK and Denmark are the [world’s] most regular and prolific sequencers,” pointed out Emma Hodcroft, a viral geneticist at the University of Bern in Switzerland. “So the variant could be elsewhere and not detected yet. More co-ordinated sequencing efforts regionally and globally would help us monitor variants.”

“英国和丹麦是（全球）进行基因组测序最频繁和最多的国家。”瑞士伯尔尼大学（University of Bern）病毒遗传学家埃玛·霍德克罗夫特（Emma Hodcroft）表示。“因此，这一变种可能存在于其他地区而尚未被检测出来。在区域和全球范围进行更多的协同测序工作，将有助于我们监测变种。”

All viruses mutate and B.1.1.7 is not the first variant to cause concern. Examples include the D614G mutation that emerged early in the pandemic and moderately increases the transmissibility of Covid-19. That strain spread from Spain to the rest of Europe over the summer. The Y453F mutation arose in Danish mink but has not spread widely in other countries.

所有病毒都会变异，B.1.1.7 也不是引发担忧的首例变种。其他变种还包括D614G，该变种出现于疫情初期，它小幅增加了COVID-19 的传染性。该毒株在今年夏天从西班牙蔓延至欧洲其他地区。Y453F突变源于丹麦水貂，但尚未在其他国家广泛传播。 OSkCAJ00DLA+2/5tW0E47avu2wmaPnVgsp+VwCFs2n6NNTHkrrFyRfcIG5r9bVhl