A coronavirus variant first detected in South Africa has now spread to several other countries, including Israel and Belgium, prompting a spate of travel restrictions across Europe, Asia, and North America.

首次在南非发现的新冠病毒变体现在已经传播到了另外几个国家，比如以色列和比利时。新冠病毒变体的发现和传播引发了欧洲、亚洲和北美地区采取了一连串的旅行限制措施。

（koto_feja/E+/Getty Images）

Spate：一连串，接二连三（通常指不愉快的事物）

The new variant, called Omicron, carries a concerning number of mutations that could make it more transmissible or more likely to cause severe disease than the Delta variant, public-health experts say.

据公共卫生专家介绍，被称为“奥密克戎”（Omicron）的新病毒变体携带有大量令人担心的突变，因此其比德尔塔病毒变体更加容易传播或更加容易引起严重疾病。

Mutation：（生物物种的）突变，变异

The World Health Organization labeled Omicron a "variant of concern" on Friday – a designation given to variants like Delta that require scrutiny from public-health officials.

世界卫生组织于周五将“奥密克戎”标记为“需要关注的变异体”-这个名称专门用于命名类似于德尔塔这样的，需要公共卫生官员留意的变体。

Preliminary evidence suggests that Omicron may increase the risk of reinfection relative to other variants of concern, WHO said.

据WHO介绍，初步证据表明，与其他需要关注的变异体相比，“奥密克戎”可能会增加二次感染的风险。

But scientists have barely begun to examine Omicron's threat: Fewer than 100 of the variant's genome sequences have been reported globally, compared with Delta's more than 2.8 million sequences.

尽管如此，科学家们尚未开始仔细研究“奥密克戎”所带来的威胁：与德尔塔超过280万个序列相比，在全球所报告的“奥密克戎”变异体的基因序列还不到100个。

"We don't know very much about this variant yet," Maria van Kerkhove, WHO's technical lead on COVID-19, said at a Thursday briefing. "What we do know is that this variant has a large number of mutations, and the concern is that when you have so many mutations, it can have an impact on how the virus behaves."

WHO 新冠肺炎技术主管Maria van Kerkhove在周四的情况介绍会上表示：“我们对该病毒变体知之甚少。我们所了解的是该变体有大量的变异。我们所担心的是，当一个变体有如此多的变异时，它会对病毒的表现产生影响。”

She added: "It will take a few weeks for us to understand what impact this variant has."

她补充表示：“我们需要花几周来了解这一变体所产生的影响。”

Many scientists are hoping for answers much sooner than that, Katelyn Jetelina, an epidemiologist at UTHealth School of Public Health, told Insider.

得克萨斯大学休斯敦公共卫生学院的流行病学家Katelyn Jetelina向Insider表示，许多科学家希望能够在更短的时间内获得答案。

The variant could be lying undetected in some parts of the globe, she said.

她表示，这一变体可能存在于地球的某些地方且尚未被发现。

"I would not be surprised if it's already landed in the US," Jetelina said. "We've already seen that this has been transmitting in communities like Turkey, Egypt, Belgium, Israel."

“如果说病毒已经进入美国，我一点都不会意外，”Jetelina表示。“我们已经看到这一变体已经在土耳其、埃及、比利时和以色列传播。”

Omicron contains several new, unfamiliar mutations

“奥密克戎”含有数个新的、不为人们所熟悉的变异

South African researchers identified the first Omicron case on November 9, then reported the variant to WHO on Wednesday.

南非研究人员在11月9日发现了首个“奥密克戎”病例，并于周三向WHO报告了该病毒变体。

Scientists are hopeful that they spotted the variant early, since the majority of known cases are still concentrated in southern Africa.

让科学家们抱有希望的是，他们在早期就发现了病毒变体，而且绝大部分已知案例都集中在非洲南部。

"South Africa has one of the best genomic surveillance systems in the world, so we know that they're really constantly evaluating this virus," Jetelina said. "For them to have 'only' detected 100 cases thus far in South Africa really gives us hope that this is the beginning stages of spread."

“南非是世界上拥有最好的基因组监管系统的国家之一，所以我们确信，他们确实是在持续性地对该病毒进行评估，”Jetelina表示。“目前在南非仅发现100个病例确实带给了我们希望，因为这意味着病毒传播还处于初始阶段。”

Still, a number of markers suggest that Omicron is highly transmissible relative to other coronavirus variants.

然而，大量标记物表明，与其他新冠病毒变体相比，“奥密克戎”非常具有传染性。

For one, South Africa's coronavirus cases have risen sharply over the past few weeks: Average daily cases have risen thirteenfold since the variant was first discovered on November 9, from about 275 to 3,700 cases per day, according to Johns Hopkins University data.

比如说，南非新冠病例在过去数周出现激增。根据约翰霍普金斯大学的数据，自从变体在11月9日被第一次发现后，南非的日平均病例增长了13倍，从每天大约275例增加到了3700例.

Omicron also contains several worrisome mutations found in other variants of concern – including Delta and Alpha – that could help it spread, render vaccines less effective, or lead to more severe disease.

“奥密克戎”还含有数个令人担忧的的变异。这些变异也存在于其他令人关注的变体，包括德尔塔和阿尔法中。这些变异使病毒变体更易传播，使疫苗效果有所减弱或导致更加严重的疾病。

The new variant carries some unfamiliar mutations, as well.

新变体还携带有一些我们不熟悉的变异。

"There are a number of mutations that we don't have any information about," Jetelina said. "They've never seen them on previous variants of concern. So, I think, one of the first questions is: What are these? Do we need to worry about them or not?"

Jetelina表示：“有大量变异我们还不了解。这些变异是此前需要关注的变体中所没有的。因此，我最想问的问题之一就是：这些变异是什么？我们是否需要关注？还是无需关注？”

So far, scientists have identified 32 mutations on the variant's spike protein – the protruding crownlike bumps on the surface of the virus that help it invade our cells.

目前，科学家们已经在变体的刺突蛋白中发现了32个变异。刺突蛋白就是病毒表面凸起的、类似于桂冠的隆起，这些隆起可以帮助病毒侵入我们的细胞。

spike protein：刺突蛋白

Other variants of concern have had fewer spike mutations.

其他需要关注的变体并没有这么多的突变。

"The spike protein is basically the key into our cells to infect us, so once that protein changes for better or for worse, then we need to really pay attention to it," Jetelina said. "That is probably what is creating this increase in cases that we're seeing in South Africa right now."

“刺突蛋白是进入我们的细胞并使我们感染病毒的关键。因此，一旦蛋白发生好转或恶化，那么我们就需要去关注它。这很可能就是导致南非病例目前增加的原因。”

Public-health experts say there's no need for panic yet 

公共健康专家表示，目前还无需恐慌

A higher number of mutations doesn't necessarily make a variant deadlier or more transmissible – nor does it suggest on its own that Omicron will pose a greater challenge to vaccines than other variants of concern.

变异数量增加并非一定代表变体更致命或更加易于传播-也并非意味着“奥米克戎”与其他需要关注的变体相比，会对疫苗造成更大的挑战。

"We don't know yet if this new variant is outcompeting Delta," Jetelina said. "We also still don't know if it will evade our vaccines yet, either."

“我们目前还不清楚这个新的病毒变体是否会比德尔塔还要厉害。另外，我们也不清楚该变体是否会侵入我们的疫苗。”Jetelina表示。

Scientists are still waiting on lab studies to determine how well coronavirus antibodies – either from natural infection or vaccines – hold up against Omicron.

科学家们还在等待实验室的研究结果，以了解新冠病毒抗体（无论来自于天然感染或疫苗）是如何对抗“奥密克戎”的。

They're also watching carefully to see how quickly the variant spreads across the globe, particularly in countries with higher vaccination rates. (South Africa has fully vaccinated just 24 percent of its population, compared with 59 percent in the US.)

他们也在仔细观察变体会以怎样的速度在全球蔓延，特别是在疫苗接种率较高的国家蔓延。（南非的接种率仅为24%，而美国的接种率为59%。）

"We really just need to hold tight to see how this plays out and what our next move is," Jetelina said.

“我们真正要做的就是静观其变，观察这个新变体到底如何表现以及我们接下来的应对举措。”Jetelina表示。

Moderna, BioNTech-Pfizer, and Johnson & Johnson all said on Friday that they were testing how well their vaccines protected against Omicron.

 莫德纳（Moderna）、BioNTech-辉瑞和强生都于周五表示，他们目前正在测试疫苗对“奥密克戎”的防疫效果。

People who have been fully vaccinated and wear masks in public indoor settings shouldn't feel compelled to change their behavior right now, Jetelina added.

已经全程接种疫苗并在公共室内场所佩戴口罩的人们无需立刻改变行为方式，Jetelina补充表示。

Mike Ryan, the executive director of WHO's health-emergencies program, shared a similar message on Thursday.

WHO 卫生突发项目执行主管Mike Ryan于周四分享表达了同样的观点。

"Viruses evolve, and we pick up variations. It's not the end of the world. The sky is not falling in," he said. "There is this idea that we're just waiting for the next variant, and I don't want people to spend their lives worrying about that every day."

“病毒会进化，而我们也会发现病毒的变异。世界不会因此毁灭。天也不会塌下来。我们正在等着病毒的下一次变异。我不希望人们整天都把时间花在担心病毒变异上面。”

原文来源：SCIENCE ALERT  翻译&编辑：Sarah