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研究表明，南非新冠病毒变体的一个突变可能会影响抗体与病毒结合的能力，降低疫苗效果。
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全文共 881 个词，by Clive Cookson, Joseph Cotterill in London, in Johannesburg
The new coronavirus variant linked to a surge in Covid-19 cases in South Africa is not only more infectious than previous forms of the virus but could make some vaccines less effective.
与南非新型冠状病毒肺炎（COVID-19，即 2019 冠状病毒病）病例激增有关的新冠病毒新变种不只比原先的病毒更具传染性，而且还可能让一些疫苗的效果减弱。
Scientists racing to understand the new strain said they still expected the current crop of approved vaccines to work but were worried that a specific mutation, also identified in a new variant in Brazil, could affect the way the virus responds.
科学家们正在加快研究这种新毒株，他们表示仍然预计目前已获批的疫苗有效，但担心一种特殊突变——也在巴西的一个新变种中发现——可能会影响病毒对疫苗的反应方式。
Photo credit:Getty Images
“At this moment, we think that a vaccine could be a little less effective,” Professor Tulio de Oliveira, of the University of KwaZulu-Natal, who is leading South Africa’s scientific effort to understand the 501Y.V2 strain, told the Financial Times. “[But] between all the varieties of vaccines that are coming to the market, we still have strong belief that some of them will be very effective.”
“目前，我们认为疫苗的效果可能会变差一些。”南非夸祖鲁-纳塔尔大学（University of KwaZulu-Natal）的图略·德奥利韦拉（Tulio de Oliveira）教授告诉英国《金融时报》：“（但是）在即将上市的所有疫苗品种中，我们仍然坚信其中一些疫苗将非常有效。”德奥利韦拉是南非科学界研究该 501Y.V2 毒株的领军人物。
The mutation in question, called E484K, changes the “receptor binding domain” — a key part of the spike protein that the virus uses to enter human cells. This is also an important site at which neutralising antibodies induced by infection or vaccination bind to the virus.
这种被称为E484K的突变改变了“受体结合域”（receptor binding domain），也就是病毒用来进入人类细胞的刺突蛋白的关键部分。这也是感染或疫苗接种诱导产生的中和抗体与病毒结合的重要部位。
A team at the Fred Hutchinson Cancer Research Center in Seattle has assessed the ability of antibodies taken from people previously infected with Sars-Cov-2 to neutralise various new strains of coronavirus.
西雅图弗雷德·哈钦森癌症研究中心（Fred Hutchinson Cancer Research Center in Seattle）的一个团队评估了从曾经感染新冠病毒（SARS-CoV-2）的人身上提取的抗体中和各种新毒株的能力。
Their study, released on Tuesday but not peer-reviewed, found that “emerging lineages in South Africa and Brazil carrying the E484K mutation will have greatly reduced susceptibility to neutralisation by the... serum antibodies of some individuals”. However, the effect was much stronger in some people than others, the paper said.
他们的研究于周二发表，但未经同行评审，研究发现“南非和巴西出现的携带E484K突变的谱系将大大降低某些个体的血清抗体对中和的敏感性”。不过，该论文写道，这种影响在一些人身上要比其他人强烈得多。
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Prof de Oliveira’s team in South Africa have reached similar conclusions. “This finding about antibody neutralisation was highlighted very strongly in our paper,” he said. “There is a reason to be concerned.”
德奥利韦拉教授的南非团队也得出了类似的结论。“这项关于抗体中和的发现是我们论文特别强调的部分，”他表示，“有理由关切这个问题。”
Prof de Oliveira added that his team had spent “the last 15 days, working day and night, with the top laboratories in South Africa” and would release “strong preliminary results” soon.
德奥利韦拉教授补充说，他的团队“在过去 15 天里与南非的顶级实验室一起夜以继日地工作”，并将很快公布“有力的初步结果”。
The 501Y.V2 variant emerged in August in South Africa’s Nelson Mandela Bay in the Eastern Cape, before spreading to other provinces as the country’s second wave of Covid-19 infections accelerated in recent weeks. Out of South Africa’s 1.1m total confirmed cases to date, about 100,000 have been in the past seven days.
501Y.V2 变体于去年 8 月出现在南非东开普省的纳尔逊·曼德拉湾（Nelson Mandela Bay），后来，随着最近数周南非第二波新冠疫情加速蔓延，该变体传播到其他省份。到目前为止，南非共有 110 万确诊病例，其中约 10 万例是在过去 7 天内确诊的。
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Coronavirus variants are emerging around the world as Sars-Cov-2 passes between tens of millions of people. On average, the virus accumulates about two mutations per month but it can change more quickly under some circumstances — for example within an individual who has a suppressed immune system and remains infected for many weeks.
随着新冠病毒在数千万人之中蔓延，其变种正在世界各地涌现。平均而言，该病毒每月累积约两次突变，但在某些情况下，它的变化会更快——例如，在免疫系统受抑制、持续感染多周的个体中。
The South African and Brazilian strains share several mutations with the fast-spreading B.1.1.7 variant in the UK, which made its first known appearance in Kent in late September. But B.1.1.7 does not have the E484K mutation.
南非和巴西的毒株与在英国快速蔓延的B.1.1.7 变体有几个相同的突变，后者于 9 月下旬在肯特郡首次被发现。但B.1.1.7 不存在E484K突变。
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For this reason, “most scientists with a view on these variants are more concerned about the South African one than the Kent one,” said Francois Balloux, director of the University College London Genetics Institute.
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，出于这个原因，“大多数对这些新变种有看法的科学家更担心南非的新变种，而不是肯特的新变种。”
Matt Hancock, the UK health secretary, has expressed concern about the South African variant on several occasions saying on Monday that he was “incredibly worried”.
英国卫生大臣马特·汉考克（Matt Hancock）已在多个场合表达对南非新变种的担忧，他周一表示自己“非常担心”。
Prof de Oliveira described Mr Hancock’s comments, which were perceived by some in South Africa as an attempt to deflect attention from the UK, as “very unfortunate”.
一些南非人认为汉考克是为了转移人们对英国的关注。德奥利韦拉教授称汉考克的说法“非常不合适”。
“We are really trying our best to see if that politicisation can decrease,” he said. “We are working very closely with British scientists. We have been exchanging data and knowledge on an almost daily basis on the scientific front. Our job as the global scientific community is to try and de-escalate that kind of tension.”
“我们确实在尽最大努力让这种政治化减少。”他说，“我们正在与英国科学家密切合作。我们几乎每天都在科学战线上交换数据和知识。作为全球科学界的一员，我们的工作就是努力缓和这种紧张局势。”
The UK and South Africa — unlike most other countries — have conducted extensive genomic sequencing throughout the pandemic, enabling health officials to track mutations quickly. This could mean that other more infectious variants are already spreading in other countries undetected.
与大多数其他国家不同，英国和南非在疫情期间进行了广泛的基因组测序，使卫生官员能够迅速追踪到突变。这可能意味着，其他更具传染性的病毒变种已经在其他国家传播了，只是没有发现。
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So far, no new Sars-Cov-2 variant is known to cause more severe disease than the original virus that emerged in China at the end of 2019, but more rapid rates of transmission have piled greater pressure on hospitals and health systems.
到目前为止，还没有发现比 2019 年底中国出现的原始病毒导致更严重疾病的新冠病毒新变种，但更快的传播速度给医院和卫生系统带来了更大的压力。
“The main take-home message is that we should not be playing with this virus by letting it transmit for so long,” said Prof de Oliveira. “More than ever, this is a global problem and we should be looking for a global coalition to respond.”
“关键教训在于，我们不该拿这个病毒开玩笑，放任它传播这么久。”德奥利韦拉教授说，“这是一个前所未有的全球性问题，我们应该寻求建立一个全球联盟来应对。”