关于病毒变异株，你应该了解这五件事 | 盖茨笔记

I’ve spent a lot of time over the last year meeting with colleagues at our foundation and around the world about ways to test for, treat, and prevent COVID-19. In recent months, the experts in those meetings are increasingly asking the same question: How will new variants impact our efforts to end the pandemic?

去年我花了很多时间与我们基金会和世界各地的同事会面，讨论关于检测、治疗和预防新冠肺炎的方法。在最近的几个月中，参与这些会议的专家们越来越多地提出了相同的问题：新的病毒变异株将如何影响我们终结疫情的努力？

The world has come a long way in the fight against COVID-19, but new variants of the virus could threaten progress we’ve made over the past year. Here are five things you should know if you want to understand how variants are (and aren’t) complicating the pandemic.

世界在与新冠肺炎的斗争中走过了一条漫长道路，但病毒的新变异株可能会威胁到我们在过去一年中取得的进展。你如果想了解病毒变异株如何让（或者如何不让）疫情变得更复杂，就应该了解以下五件事。

01

  If you’ve ever gotten a flu shot, you’ve already dealt with a virus variant.

如果你曾经接种过流感疫苗，你就已经接触过病毒变异株了

Viruses evolve all the time. Unless you work on infectious diseases, the idea of a “variant” might seem new and scary—but there’s nothing particularly unusual about them. Influenza’s ability to mutate quickly (I’ll talk more about this in the next section) is why we get a new flu shot every year. We need to update the vaccine annually to keep up with constantly shifting flu virus strains.

病毒一直在进化。除非你从事与传染病相关的工作，否则“变异”这个概念可能看起来很新奇、很可怕，但它们并没有什么特别之处。流感病毒快速变异的能力（我将在下一节中详细介绍）正是我们每年都要注射新的流感疫苗的原因。我们需要每年更新疫苗，以适应不断变异的流感病毒株。

To understand why the virus that causes COVID-19 is changing, you need to understand how it works (or spreads) in your body. The coronavirus—like all viruses—has only one goal: to replicate itself. Every time the virus invades your cells, it tricks the cell into following the instructions encoded in its RNA to make more copies of the virus.

要了解为什么新冠肺炎病毒在不断变化，你需要了解它在你体内工作（或传播）的方式。新冠病毒和其他所有病毒一样，它只有一个目标：自我复制。每当病毒入侵你的细胞时，它就会诱使细胞按照其核糖核酸（RNA）中编码的指令制造更多的病毒复制体。

When the cell is making a new virus, it has to copy those instructions. If you’ve ever had to take a typing class in school, you know how hard it is to retype something without making a mistake. The code for the virus that causes COVID-19 is around 30,000 letters long. That’s a lot of opportunities to mess up—which the coronavirus often does.

当细胞制造新病毒时，它必须复制那些指令。如果你曾经在学校上过打字课，那么你会知道在不犯错误的情况下，将某样东西反复打出来有多困难。导致新冠肺炎的病毒代码有大约3万个字母，这就造成了很多犯错误的机会，而新冠病毒经常会犯错误。

Most mistakes lead to a virus that either is functionally identical or can’t replicate. But every once in a while, there’s a change that makes it easier for the virus to infect people or evade the immune system. When that change starts to spread through a population, a new variant emerges.

大多数的错误会造成病毒要么在功能上相同，要么无法复制。但是每隔一段时间，就有一种变化使病毒更容易感染人或逃避免疫系统。当这种变化开始在人群中传播时，一个新的病毒变异株就诞生了。

02

 We’re seeing the same mutations pop up again and again. That may be good news.

我们看到相同的变异不断出现，这可能是个好消息

All viruses evolve, but not all viruses evolve at the same rate and in the same way. Some, like the flu, change rapidly. Others mutate slowly. Fortunately for us, SARS-CoV-2 is in the latter camp. It mutates about half as fast as the influenza virus.

所有病毒都在进化，但并非所有病毒都以相同的速度和方式进化。有些病毒（比如流感）变化迅速，另一些则变异缓慢。对我们来说幸运的是，新冠病毒属于后者。它的变异速度大约是流感病毒的一半。

I know it feels like new variants are popping up all the time right now. That’s because there is so much virus circulating around the world, giving it more opportunities to change. Once case numbers go down, I suspect we’ll see new variants emerge much less often.

我知道现在感觉好像新的变异株一直在出现。那是因为世界上有如此多的病毒在传播，这给病毒带来了更多的机会去改变。一旦病例数下降，我推测我们会看到新变异株出现的频率大大降低。

Compared to influenza viruses—which are made up of eight genetic segments that can be rearranged in lots of different ways—the coronavirus is a much simpler virus. The most notable mutations we’ve seen so far have happened in the same spot: the spike protein that sticks out of the surface of the virus.

与流感病毒相比（流感病毒由八种基因片段组成，这些片段可以通过许多不同方式重新排列组合），冠状病毒是一种简单得多的病毒。迄今为止，我们看到的最明显突变都发生在同一位置：从病毒表面伸出的刺突蛋白。

That spike protein is the key to COVID’s spread. Its shape is what enables the virus to grab onto human cells. If the spike protein changes just a little, it might bind with cells more effectively (which makes the virus more transmissible) or become harder for the immune system to target (which makes people more susceptible to it). But if it changes too much, the virus can no longer gain the entry that’s key to its lifecycle.

这种刺突蛋白是新冠肺炎传播的关键，它的形状使病毒能够抓住人体细胞。如果刺突蛋白稍有变化，它可能会更有效地与细胞结合（这使病毒更易传播），或者使它更难被免疫系统锁定（使人们更容易感染它）。但是，如果变化太大，该病毒将无法再获得对其生命周期至关重要的入口。

That limited capacity for change may explain why we keep seeing the same mutations appear in different places rather than lots of distinct variations. Both B.1.1.7 (which was originally detected in the UK) and B.1.351 (which was first found in South Africa) evolved independently, yet they share a number of the same mutations. There’s clearly something about these specific mutations that makes them more likely to succeed than other changes.

有限的变化能力可能解释了为什么我们不断看到相同的突变——而不是很多不同的变化——出现在不同的地方。B.1.1.7（最初在英国发现）和B.1.351（最早是在南非发现）是独立进化的，但是它们却有许多相同的突变。显然有什么东西让这些特定突变比其他变化更容易成功。

Some experts think we may have already seen the most concerning mutations that this virus is capable of. But COVID-19 has surprised us before, of course, and it could surprise us again.

一些专家认为，我们可能已经看到了新冠病毒能够产生的最令人担忧的突变。但是，新冠肺炎曾让我们感到惊讶，它也可能再次让我们感到震惊。

03

The virus is changing, but the path to ending the pandemic remains the same.

病毒正在改变，但通向终结疫情的道路仍然没变

For the last year, public health experts have been repeating some form of the same message: we need to contain COVID-19 as best we can until the vaccine is ready and available for everyone.

去年，公共卫生专家一直以不同形式在重复着同一信息：我们需要尽可能控制新冠疫情，直到疫苗出现并能够提供给所有人。

The good news is that many of the vaccines being used today appear to prevent severe disease, even from the new variants. This is a tribute to how effective the vaccines are in general. We still need a lot more data about how effective every vaccine is against the different variants, but many of the early numbers are reassuring (especially out of Israel, where many people are already vaccinated and the B.1.1.7 strain is dominant).

好消息是，正在被使用的许多新冠疫苗似乎都可以预防重症，甚至可以预防新的变异株。这说明疫苗总体上很有效。但我们仍然需要更多的数据来了解每种疫苗对不同变异株的有效性，许多早期数据让人感到欣慰（尤其是来自以色列的数据，那里已经有许多人接种了疫苗，而且B.1.1.7毒株占了主导地位）。

The big question now is whether we need to update the vaccines to target the variants. Regulators and drug companies are working on a modified vaccine that could be out in a couple months if it’s deemed necessary. Here in the United States—where the majority of people will likely be vaccinated by the end of the summer—some people may end up getting a booster shot that protects against additional strains.

现在的大问题是，我们是否需要针对这些变异株更新疫苗。监管机构和制药公司正在研究一种修饰过的疫苗，如果有必要，可能会在几个月内推出。在美国, 大多数人可能会在夏天结束前接种疫苗, 有些人可能最终还会接种一剂加强针，以保护他们不感染新的变异株。

For now, the key is to keep following best practices. The best way to prevent new variants from emerging is by stopping transmission of the virus altogether. If we remain vigilant about social distancing, wearing a mask, and getting vaccinated, we will bring the pandemic to an end much sooner.

目前，关键是要遵循最佳做法。防止出现新变异株的最佳方法是完全阻止病毒的传播。如果我们保持警惕、保持社交距离、戴口罩并且接种疫苗，我们就会更早地结束疫情。

04

Variants make it even more important that vaccines are made available everywhere.

变异株让疫苗做到人人可及变得愈发重要

COVID-19 anywhere is a threat to health everywhere. That’s true with the original virus, and it’s true when it comes to variants.

任何地方的新冠疫情都会对所有地方的健康构成威胁。最初的新冠病毒是这样，而病毒变异株也是如此。

The more the virus that causes COVID-19 is out there in the world, the more opportunities it has to evolve—and to develop new ways of fighting our defenses against it. If we don’t get the vaccine out to every corner of the planet, we’ll have to live with the possibility that a much worse strain of the virus will emerge. We could even see a new variant emerge that evades existing vaccines altogether.

世界上导致新冠肺炎的病毒越多，它就有更多的机会来进化，并形成新的方法来对抗我们的防御措施。如果我们不把疫苗带到地球的每一个角落，我们就将不得不承受出现一种更糟病毒株的可能性。我们甚至可能看到一种新的、可以绕过所有现存疫苗的变异株的出现。

No one wants that to happen. The best way to make sure it doesn’t is by getting the vaccine out to everyone who needs it, no matter where they live. That’s why our foundation is working with governments, vaccine manufacturers, organizations like CEPI and Gavi, the Vaccine Alliance, and others to deliver COVID-19 vaccines to low-income countries through an initiative called COVAX.

没有人希望这种事情发生。确保这不会发生的最佳方法，就是将疫苗分发给需要它的每个人，无论他们身在何处。这就是为什么我们基金会与政府、疫苗制造商、流行病防范创新联盟和全球疫苗免疫联盟以及其他组织合作，通过“新冠肺炎疫苗实施计划（COVAX）”向低收入国家提供新冠疫苗。

COVAX recently announced that it’ll be able to deliver 300 million doses by mid-2021. That’s great news, but the world is going to need a lot more if we’re going to truly stamp out the threat of COVID-19.  I hope rich world countries continue to support COVAX’s work, even as life starts to get back to normal in some parts of the world over the summer.

COVAX最近宣布其将能在2021年中前分发3亿剂疫苗。这是个好消息，但是如果我们要真正消除新冠肺炎的威胁，世界将需要更多。我希望富裕国家继续支持COVAX的工作，即使世界一些地方的生活在今年夏天会开始恢复正常。

05

  We can do better next time.

我们下次可以做得更好

Virus variants are inevitable. If we ever find ourselves in a pandemic scenario again where a pathogen is spreading around the globe, we should expect to see it adapt to survive our attempts to stop it—just as we saw with COVID-19. I hope the difference next time is that we’re better prepared to spot these variants earlier.

病毒变异是不可避免的。如果我们再次置身于一场大流行，那时候一种病原体正在全球蔓延，我们应该料到它会适应我们阻止其传播的做法，就像我们在新冠病毒上看到的一样。我希望下一次的不同之处在于，我们做了更好的准备，从而能够更早地发现这些变异株。

The key will be genetic sequencing in combination with better disease surveillance. Right now, if you test positive for COVID-19, there’s a possibility that your test sample gets selected to be sequenced. This lets researchers see the exact 30,000 letter code that makes up the virus’ RNA instructions. That code gets uploaded to a database, where a computer compares the virus in your sample to all the other strains in circulation. . If you have a new strain that’s starting to pop up over and over in your area, scientists can compare the sequence data to transmission, death, and hospitalization rates to see if there’s need for concern.

关键是将基因测序与更好的疾病监测相结合。现在，如果你的新冠检测呈阳性，那么你的样本有可能被选择进行基因测序。这样一来，研究人员就可以确切地看到构成该病毒RNA指令的3万个字母代码。该代码将被上传到一个数据库，在这个数据库中，计算机会将你样本中的病毒与所有其他正在传播的病毒进行比较。如果你感染了一种新毒株，而这种新毒株在你所在的地区反复出现，科学家可以将序列数据与传播、死亡和住院率进行比较，从而判断是否需要特别的关注。

Researchers need to take a systematic approach to catch variants early. Some experts think we need to sequence at least 5 percent of all test samples to get an accurate picture of how a pathogen is mutating—although sequencing a large number of samples alone isn’t enough. The UK has analyzed nearly 8 percent of its tests and linked that data with their surveillance capabilities, which helped them see that B.1.1.7 was spreading much faster and was more lethal. South Africa was able to quickly see how vaccines worked on B.1.351 by comparing results from clinical trials there to sequenced data.

研究人员需要采取一种系统性的方法来尽早发现变异株。一些专家认为，我们需要对所有病毒测试样本中的至少5%进行基因测序，从而准确了解一种病原体是如何发生突变，尽管仅对大量样品进行测序是不够的。英国已经分析了将近8%的检测样本，并将这些数据与他们的监测能力联系起来，这帮助他们了解到B.1.1.7的传播速度更快且更致命。通过将当地临床试验结果与测序数据进行比较，南非得以快速了解疫苗如何对B.1.351变异株发挥作用。

The tools we’re putting in place to monitor variants in this pandemic will prove invaluable long after the worst of COVID-19 is behind us. Widespread sequencing should be part of any plan to prepare for the next pandemic. If you’re doing enough sequencing and comparing that data with other measures, you can see concerning variants when they first emerge. The earlier you identify a change, the more time you have to study it and, if needed, to tune vaccines and therapeutics to address any changes that have taken place.

在新冠肺炎最糟糕的情况过去之后，这些我们用来监测疫情中变异毒株的工具将被证明是非常宝贵的。在任何为下一次大流行做准备的计划中，广泛的测序应成为其中的一部分。如果你进行了足够的测序，并将该数据与其他措施进行比较，你就能在令人担心的变异株首次出现时就发现它。你越早发现一种变化，就有越多时间去研究它，并在必要时调整疫苗和治疗方法来应对已经发生的任何变化。

There’s no doubt that variants complicate our efforts to bring an end to this pandemic. Even once the worst is behind us, we’ll need to remain vigilant. Fortunately, we know what we need to do to stop them from emerging. For now, the best thing you can do to protect yourself is to follow public health guidelines and get vaccinated as soon as you’re eligible.  

毫无疑问，变异株使我们终结疫情的工作变得更加复杂。即使最坏的情况已经过去，我们也需要保持警惕。幸运的是，我们知道我们需要做什么来阻止变异株出现。目前，你能采取的最佳自我保护方式，就是遵守公共卫生指南，并且在你符合条件的情况下尽快接种疫苗。