這些天我被問得最多的一個問題是：世界何時才能回到去年12月新冠病毒大流行之前的狀態？我的答案始終如一：當我們得到一種近乎完美的特效藥的時候，或者當地球上幾乎所有人都接種了新冠疫苗的時候。

One of the questions I get asked the most these days is when the world will be able to go back to the way things were in December before the coronavirus pandemic. My answer is always the same: when we have an almost perfect drug to treat COVID -19, or when almost every person on the planet has been vaccinated against coronavirus.

The former is unlikely to happen anytime soon. We’d need a miracle treatment that was at least 95 percent effective to stop the outbreak. Most of the drug candidates right now are nowhere near that powerful. They could save a lot of lives, but they aren’t enough to get us back to normal.

前者不太可能在短期內實現。我們需要一種有效率達到95%的療法來遏制疫情。就目前而言，大多數候選藥物的效力都遠沒有那麼強大。它們可以挽救很多生命，但它們不足以讓我們恢復正常生活。

Which leaves us with a vaccine.

所以，我們只能寄希望於疫苗了。

Humankind has never had a more urgent task than creating broad immunity for coronavirus. Realistically, if we’re going to return to normal, we need to develop a safe, effective vaccine. We need to make billions of doses, we need to get them out to every part of the world, and we need all of this happen as quickly as possible.

形成廣泛的新冠病毒免疫力已經成為人類最為緊迫的任務。實際上，如果想要恢復正常生活，我們就需要開發出一種安全有效的疫苗，需要生產數十億劑並供應到世界各地，並且這一切需要盡快實現。

That sounds daunting, because it is. Our foundation is the biggest funder of vaccines in the world, and this effort dwarfs anything we’ve ever worked on before. It’s going to require a global cooperative effort like the world has never seen. But I know we’ll get it done. There’s simply no alternative.

這聽起來令人氣餒，因為確實很難。蓋茨基金會是世界上最大的疫苗資助者，但我們這次所面臨的挑戰遠遠大於先前從事的任何工作。這需要全球開展前所未有的通力合作。但我知道我們終將成功。除此之外別無選擇。

Here’s what you need to know about the race to create a COVID-19 vaccine.

新冠疫苗的開發工作正與時間賽跑，以下是你需要知道的事。

The world is creating this vaccine on a historically fast timeline.

世界正以前所未有的速度開發新冠肺炎疫苗

Dr. Anthony Fauci has said he thinks it’ll take around eighteen months to develop a coronavirus vaccine. I agree with him.

安東尼·福奇博士認為大約需要18個月才能開發出新冠肺炎疫苗，我同意他的觀點。

Although eighteen months sounds like a long time, this would be the fastest scientists have created a new vaccine. Development usually takes around five years. Once you pick a disease to target, you have to create the vaccine and test it on animals. Then you begin testing for safety and efficacy in humans.

雖然18個月聽起來很長，但這將是科學家們迄今為止開發速度最快的新疫苗。開發疫苗通常需要五年左右的時間，一旦你選擇了一種疾病作為目標，你就必須研製出疫苗並在動物身上進行試驗。接下來，你可以開展人體試驗，測試疫苗的安全性和有效性。

Safety and efficacy are the two most important goals for every vaccine. Safety is exactly what it sounds like: is the vaccine safe to give to people? Some minor side effects (like a mild fever or injection site pain) can be acceptable, but you don’t want to inoculate people with

something that makes them sick.

安全性和有效性是每種疫苗最重要的兩個目標。安全性就是它的字面意思：給人們接種這個疫苗安全嗎？一些輕微的副作用（如輕微發燒或接種部位的疼痛）是可以被接受的，但是你不希望人們因為接種疫苗而生病。

Efficacy measures how well the vaccine protects you from getting sick. Although you’d ideally want a vaccine to have 100 percent efficacy, many don’t. For example, this year’s flu vaccine is around 45 percent effective.

有效性衡量的是疫苗對你的保護效力。儘管理想情況下你希望疫苗有100%的效力，但是很多疫苗並沒有這麼完美。例如，今年流感疫苗的有效率約為45% 。

To test for safety and efficacy, every vaccine goes through three phases of trials:

為了測試疫苗的安全性和有效性，每種疫苗都要經過三個階段的臨床試驗：

Phase one is the safety trial. A small group of healthy volunteers gets the vaccine candidate. You try out different dosages to create the strongest immune response at the lowest effective dose without serious side effects.

一期臨床試驗是安全試驗，由一小組健康的志願者接種候選疫苗。你可以嘗試使用不同的劑量，目的是用最低的有效劑量產生最強的免疫應答卻又不會出現嚴重副作用。

Once you’ve settled on a formula, you move onto phase two, which tells you how

well the vaccine works in the people who are intended to get it. This time, hundreds of people get the vaccine. This cohort should include people of different ages and health statuses.

在確定一套方案後，你會進入二期臨床試驗，它將會告訴你疫苗作用於接種人群的效果如何。這一次，數百人將接種疫苗，這個群體應該包括不同年齡和不同健康狀況的人。

Then, in phase three, you give it to thousands of people. This is usually the longest phase, because it occurs in what’s called “natural disease conditions.” You introduce it to a sufficient number of people that are likely already at the risk of infection by the target pathogen, and then wait and see if the vaccine reduces how many people get sick.

接著在三期臨床試驗中，你會讓數千人進行接種。這通常是最長的一個階段，因為它發生在所謂的“自然疾病條件”下。你給足夠多的可能已經暴露在目標病原體感染風險下的人接種疫苗，然後看疫苗能多大程度減少患病人數。

After the vaccine passes all three trial phases, you start building the factories to manufacture it, and it gets submitted to the WHO and various government agencies for approval.

在疫苗通過上述三期臨床試驗後，你還需要有生產疫苗的工廠，並將疫苗提交到世界衛生組織和各個政府機構進行審批。

This process works well for most vaccines, but the normal development timeline isn’t good enough right now. Every day we can cut from this process will make a huge difference to the world in terms of saving lives and reducing trillions in economic damage.

這個過程適用於大多數疫苗，但常規的開發時間表顯然不適合新冠疫苗。我們從這一過程中節省下來的每一天，都將對世界產生巨大影響，不僅能挽救生命，而且可以減少數万億的經濟損失。

So, to speed up the process, vaccine developers are compressing the timeline. This graphic shows how:

因此，為了加快這一進程，疫苗開發人員正在壓縮時間，從下面這張圖可以看到我們是如何做到的。

In the traditional process, the steps are sequential to address key questions and unknowns. This can help mitigate financial risk, since creating a new vaccine is expensive. Many candidates fail, which is why companies wait to invest in the next step until they know the previous step was successful.

在傳統過程中，這些步驟是按順序進行的，從而解決關鍵問題和未知因素。同時這樣也有助於降低金融風險，因為開發一種新疫苗耗資不菲。許多候選疫苗最終都失敗了，這就是為什麼企業需要等到明確上一步成功後才會繼續投資下一步工作。

For COVID-19, financing development is not an issue. Governments and other organizations (including our foundation and an amazing organization called the Coalition for Epidemic Preparedness Innovations) have made it clear they will support whatever it takes to find a vaccine. So, scientists are able to save time by doing several of the development steps at once. For example, the private sector, governments, and our foundation are going to start identifying facilities to manufacture different potential vaccines. If some of those facilities end up going unused, that’s okay. It’s a small price to pay for getting ahead on production.

對於新冠疫苗而言，開發資金不是問題。各國政府和其他機構——包括我們的基金會和一個叫做“流行病防範創新聯盟”（Coalition for Epidemic Preparedness Innovations，CEPI）的了不起的組織——已經明確表示，將不惜一切代價支持疫苗開發。因此，科學家們可以通過平行進行幾個開發步驟來節省時間。例如，私營部門、政府和我們的基金會將開始確定生產不同潛在疫苗的設施。即使部分設施最終不被使用，那也沒關係。為了縮短疫苗生產進程，這只是一個小小的代價。

Fortunately, compressing the trial timeline isn’t the only way to take a process that usually takes five years and get it done in 18 months. Another way we’re going to do that is that by testing lots of different approaches at the same time .

所幸，壓縮臨床試驗時間並不是將疫苗開發週期從五年縮短至18個月的唯一方法。我們即將採取的另一個措施是同時試驗許多不同的方法。

There are dozens of candidates in the pipeline

數十個候選疫苗正在籌備中

As of April 9, there are 115 different COVID-19 vaccine candidates in the development pipeline. I think that eight to ten of those look particularly promising. (Our foundation is going keep an eye on all the others to see if we missed any that have some positive characteristics, though.)

截至4月9日，已經有115個不同的新冠肺炎候選疫苗正在開發中。我認為其中的8到10個看起來很有前景。（儘管如此，我們的基金會還是會密切關注所有其他疫苗，以免遺漏了那些具有技術潛力的疫苗。）

The most promising candidates take a variety of approaches to protecting the body against COVID-19. To understand what exactly that means, it’s helpful to remember how the human immune system works.

最有前景的候選疫苗採取了各種方法來保護人體免受新冠病毒的侵害。這句話究竟意味著什麼？讓我們先來了解人類免疫系統是如何工作的。

When a disease pathogen gets into your system, your immune system responds by producing antibodies. These antibodies attach themselves to substances called antigens on the Surface of the microbe, which sends a signal to your body to attack. Your immune system keeps a record of every microbe it has ever defeated, so that it can quickly recognize and destroy invaders before they make you ill.

當一種病原體進入人體，你的免疫系統就會產生抗體。這些抗體附著在微生物表面稱為抗原的物質上，向你的身體發出攻擊信號。你的免疫系統會記錄它曾經擊敗過的每一種微生物，這樣就能在入侵者使你生病之前迅速識別並消滅它們。

Vaccines circumvent this whole process by teaching your body how to defeat a pathogen without ever getting sick. The two most common types—and the ones you’re probably most familiar with—are inactivated and live vaccines. Inactivated vaccines contain pathogens that have been killed . Live vaccines, on the other hand, are made of living pathogens that have been weakened (or “attenuated”). They’re highly effective but more prone to side effects than their inactivated counterparts.

疫苗能夠避免這整個過程，它能教會你的身體如何在不生病的情況下戰勝病原體。兩種最常見的類型（也是你可能最熟悉的類型）是滅活疫苗和活疫苗。滅活疫苗含有被殺死的病原體。而活疫苗是由毒性被減弱（或“減毒”）的活病原體製成的，它們非常有效，但相比同類的滅活疫苗更容易產生副作用。

Inactivated and live vaccines are what we consider “traditional” approaches. There are a number of COVID-19 vaccine candidates of both types, and for good reason: they’re well-established. We know how to test and manufacture them.

滅活疫苗和減毒活疫苗是我們所認為的“傳統”方法。這兩種類型的新冠候選疫苗有很多。原因很簡單：它們的技術都很成熟。我們知道如何測試和製造它們。

The downside is that they’re time-consuming to make. There’s a ton of material in each dose of a vaccine. Most of that material is biological, which means you have to grow it. That takes time, unfortunately.

但它們的缺點是製造起來很費時間。每劑疫苗都需要大量原材料，其中大部分是生物材料，這意味著你需要時間來培養牠們。

That’s why I’m particularly excited by two new approaches that some of the candidates are taking: RNA and DNA vaccines. If one of these new approaches pans out, we’ll likely be able to get vaccines out to the whole world much faster. (For the sake of simplicity, I’m only going to explain RNA vaccines. DNA vaccines are similar, just with a different type of genetic material.)

這就是我為什麼對目前一些候選疫苗採取的兩種新方法感到特別興奮：RNA疫苗和DNA疫苗。如果任何一個新方法獲得成功，我們都能更快地將疫苗提供給全世界。（簡單起見，我在此只解釋一下RNA疫苗，DNA疫苗的原理是近似的，只是使用不同的遺傳物質。）

Our foundation—both through our own funding and through CEPI—has been supporting the development of an RNA vaccine platform for nearly a decade. We were planning to use it to make vaccines for diseases that affect the poor like malaria, but now it’s looking like one of the most promising options for COVID. The first candidate to start human trials was an RNA vaccine created by a company called Moderna.

我們的基金會近十年來一直通過我們自己的資金和CEPI支持RNA疫苗平台的開發。我們原先計劃用它來開發疫苗抗擊那些影響貧困人群的疾病（例如瘧疾），但現在看起來它可能是抗擊新冠肺炎最有前景的方案之一。第一個開始人體試驗的候選疫苗是由一家名為Moderna的公司製造的RNA疫苗。

Here’s how an RNA vaccine works: rather than injecting a pathogen’s antigen into your body, you instead give the body the genetic code needed to produce that antigen itself. When the antigens appear on the outside of your cells, your immune system attacks them – and learns how to defeat future intruders in the process. You essentially turn your body into its own vaccine manufacturing unit.

RNA疫苗的工作原理不是將病原體的抗原註射到人體內，而是給人體提供產生抗原所需的遺傳密碼。當抗原出現在細胞外部時，你的免疫系統就會攻擊它們，並在此過程中學習如何打敗未來的入侵者。本質上就是把人體變成自己的疫苗生產部門。

There’s a catch, though: we don’t know for sure yet if RNA is a viable platform for vaccines. Since COVID would be the first RNA vaccine out of the gate, we have to prove both that the platform itself works and that it creates immunity. It’s a bit like building your computer system and your first piece of software at the same time.

不過，還有一個問題：我們目前還不能確定RNA是否是開發疫苗的可行平台。由於新冠RNA疫苗將是第一個上市的RNA疫苗，我們必須證明RNA平臺本身可行並可以產生免疫力。這有點像同時構建計算機系統和系統裡的第一個軟件。

Even if an RNA vaccine continues to show promise, we still must continue pursuing the other options. We don’t know yet what the COVID-19 vaccine will look like. Until we do, we have to go full steam ahead on as many approaches as possible.

因此，即便RNA疫苗有望成功，我們仍必須繼續尋求其他可能的方法。我們還不知道新冠疫苗會是什麼樣，在此之前，我們必須全力以赴，嘗試盡可能多的方法。

It might not be a perfect vaccine yet—and that’s okay.

它可能還不是完美的疫苗，但是沒關係

The smallpox vaccine is the only vaccine that’s wiped an entire disease off the face of the earth, but it’s also pretty brutal to receive. It left a scar on the arm of anyone who gets it. One of out every three people who got it had side effects bad enough to keep them home from school or work. A small—but not insignificant—number developed more serious reactions.

天花疫苗是世界上唯一一個將一種疾病從地球上根除的疫苗，但接種天花疫苗的過程有些痛苦。它會在接種者的手臂上留疤，每三個人中就會有一人因接種天花疫苗產生的副作用而只能暫時呆在家中，無法上學或上班。其中還會有不可忽視的小部分人會產生出更嚴重的反應。

The smallpox vaccine was far from perfect, but it got the job done. The COVID-19 vaccine might be similar.

天花疫苗遠非完美，但它完成了使命。新冠疫苗可能也會如此。

If we were designing the perfect vaccine, we’d want it to be completely safe and 100 percent effective. It should be a single dose that gives you lifelong protection, and it should be easy to store and transport. I hope the COVID-19 vaccine has all of those qualities, but given the timeline we’re on, it may not.

如果要設計一種完美的疫苗，我們希望它是百分百安全且有效。你只需要接種一劑，就可以得到終生免疫保護。而且疫苗的儲存和運輸也應該很方便。我希望新冠疫苗將會具備所有這些特性，然而鑑於我們的時間表，可能無法面面俱到。

The two priorities, as I mentioned earlier, are safety and efficacy. Since we might not have time to do multi-year studies, we will have to conduct robust phase 1 safety trials and make sure we have good real-world evidence that the vaccine is completely safe to use

正如我之前提到的，疫苗的兩個重點是安全性和有效性。由於我們可能沒有時間進行多年的研究，我們將不得不進行強有力的一期安全試驗以及良好的真實世界數據，並確保我們有充分證據表明疫苗是可以安全使用。

We have a bit more wiggle room with efficacy. I suspect that vaccine that is at least 70 percent effective will be enough to stop the outbreak. A 60 percent effective vaccine is useable, but we might still see some localized outbreaks. Anything under 60 percent won’t likely create enough herd immunity to stop the virus.

在有效性方面，我們還有一些餘地。我估計有效性至少達到70%的疫苗就足以遏制疫情。有效性達到60%的疫苗是可用的，但可能仍然會看到局部暴發的疫情。任何低於60%有效性的疫苗都不可能產生足夠的群體免疫來阻止病毒的傳播。

The big challenge will be making sure the vaccine works well in older people. The older you are, the less effective vaccines are. Your immune system—like the rest of your body—ages and is slower to recognize and attack invaders. That’s a big issue for a COVID-19 vaccine, since older people are the most vulnerable. We need to make sure they’re protected.

最大的挑戰是確保疫苗對老年人也有很好的效果。年齡越大，疫苗的效果越弱。你的免疫系統，如同你身體其他部分一樣，也會隨著年齡的增長而衰老，識別和攻擊入侵者的速度也會變慢。這對新冠疫苗來說是個大問題，因為老年人也是最容易感染新冠病毒的人群，我們需要確保他們得到保護。

The shingles vaccine—which is also targeted to older people—combats this by amping up the strength of the vaccine. It’s possible we do something similar for COVID, although it might come with more side effects. Health authorities could also ask people over a certain age to get an additional dose.

作為同樣針對老年人的疫苗，帶狀皰疹疫苗通過增加疫苗的效力來解決上述問題。針對新冠病毒，我們可以做類似的事情，儘管這可能帶來更多副作用。衛生部門也可以讓超過一定年齡的人群多接種一劑。

Beyond safety and efficacy, there are a couple other factors to consider:

除了安全性與有效性外，還有以下幾個因素需要考慮：

How many doses will it be? A vaccine you only get once is easier and quicker to deliver. But we may need a multi-dose vaccine to get enough efficacy.

要接種多少劑？只需要接種一劑的疫苗，相對更便捷、更快速。但我們可能需要接種多劑的疫苗才能獲得足夠的效力。

How long does it last? Ideally, the vaccine will give you long-lasting protection. But we might end up with one that only stops you from getting sick for a couple months (like the seasonal flu vaccine, which protects you for about six months ). If that happens, the short-term vaccine might be used while we work on a more durable one.

疫苗效力可以維持多久？理想情況下，疫苗可以提供持久的保護。但最終我們可能會得到一種只能為你提供幾個月保護的疫苗（與季節性流感疫苗類似，免疫時效大約為6個月左右）。如果真是這樣，我們很可能在研究更持久疫苗的同時，先使用短期有效的疫苗。

How do you store it? Many common vaccines are kept at 4 degrees C. That’s around the temperature of your average refrigerator, so storage and transportation is easy. But RNA vaccines need to be stored at much colder temperature—as low as -80 degrees C—which will make reaching certain parts of the world more difficult.

疫苗如何儲存？許多常見的疫苗需要儲藏在4攝氏度的條件下，這大約是一般冰箱的溫度，所以儲藏與運輸也相對簡單。但RNA疫苗需要儲藏在更低的溫度下，可能低至零下80攝氏度，將其運輸到世界某些地方會變得更加困難。

My hope is that the vaccine we have 18 months from now is as close to “perfect” as possible. Even if it isn’t, we will continue working to improve it. After that happens, I suspect the COVID-19 vaccine will become part of the routine newborn immunization schedule.

我希望18個月後誕生的新冠疫苗盡可能地接近“完美”。就算不是，我們仍將繼續努力改進它。在此之後，我認為新冠疫苗將成為新生兒常規免疫計劃中的一部分。

Once we have a vaccine, though, we still have huge problems to solve. That’s because…

就算有了疫苗，我們仍需解決一些重要問題，那是因為……

We need to manufacture and distribute at least 7 billion doses of the vaccine.

我們需要生產和分發至少70億劑疫苗

In order to stop the pandemic, we need to make the vaccine available to almost every person on the planet. We’ve never delivered something to every corner of the world before. And, as I mentioned earlier, vaccines are particularly difficult to make and store.

為了遏制大流行病，我們需要確保地球上幾乎每一個人都能接種疫苗。將某個東西送達到世界上的每一個角落，這在過去從未發生過。同時，正如我之前提到的，疫苗的生產和儲藏也非常困難。

There’s a lot we can’t figure out about manufacturing and distributing the vaccine until we know what exactly we’re working with. For example, will we be able to use existing vaccine factories to make the COVID-19 vaccine?

在明確最終會使用哪種疫苗之前，我們無法確定如何生產和分發疫苗。例如，我們能否利用現有的疫苗工廠生產新冠疫苗？

What we can do now is build different kinds of vaccine factories to prepare. Each vaccine type requires a different kind of factory. We need to be ready with facilities that can make each type, so that we can start manufacturing the final vaccine (or vaccines ) as soon as we can. This will cost billions of dollars. Governments need to quickly find a mechanism for making the funding for this available. Our foundation is currently working with CEPI, the WHO, and governments to figure out the financing.

我們現在能做的是為各種不同類型的疫苗建造工廠。每一種類型的疫苗需要不同的生產工廠。我們需要準備好生產各種疫苗的設備，從而確保當一種或多種疫苗研發完成後儘快開始生產。這將耗資數十億美元，各國政府需要迅速找到一種機制來為此提供資金。蓋茨基金會正在與CEPI、世界衛生組織及各國政府一同籌措資金。

Part of those discussions center on who will get the vaccine when. The reality is that not everyone will be able to get the vaccine at the same time. It’ll take months—or even years—to create 7 billion doses (or possibly 14 billion, if it’s a multi-dose vaccine), and we should start distributing them as soon as the first batch is ready to go.

還有一些討論集中在誰將於何時接種疫苗。現實情況是，我們無法讓所有人同時接種疫苗，而是需要數月甚至數年的時間才能製造出70億劑疫苗（如果是接種多劑疫苗，甚至可能是140億劑），我們應該在有了第一批疫苗之後立即開始進行分發。

Most people agree that health workers should get the vaccine first. But who gets it next? Older people? Teachers? Workers in essential jobs?

多數人同意衛生工作者應該優先接種疫苗。但接下來該為誰接種呢？老年人？教師？在關鍵崗位工作的人？

I think that low-income countries should be some of the first to receive it, because people will be at a much higher risk of dying in those places. COVID-19 will spread much quicker in poor countries because measures like physical distancing are harder to enact. More people have poor underlying health that makes them more vulnerable to complications, and weak health systems will make it harder for them to receive the care they need. Getting the vaccine out in low-income countries could save millions of lives. The good news is we already have an organization with expertise about how to do this in Gavi, the Vaccine Alliance.

我認為低收入國家的人民應該在第一批接種疫苗，因為他們面臨著更高的死亡風險。由於物理隔離等措施更難以實施，新冠疫情會在貧窮國家傳播得更快。更多人的基礎健康情況不佳，使他們更易出現並發症，而在薄弱的衛生系統中，他們很難獲得所需的治療。為低收入國家提供疫苗能夠挽救數百萬人的生命。好消息是，我們已經有全球疫苗免疫聯盟（Gavi）這樣的專業機構從事這方面的工作。

With most vaccines, manufacturers sign a deal with the country where their factories are located, so that country gets first crack at the vaccines. It’s unclear if that’s what will happen here. I hope we find a way to get it out on an equitable basis to the whole world. The WHO and local health authorities will need to develop a distribution plan once we have a better understanding of what we’re working with.

對於大多數疫苗而言，疫苗生產者會與工廠所在的國家簽署協議，確保該國率先獲得疫苗。目前還不清楚這種情況是否會發生。我希望我們可以找到一種方式，在公平的基礎上向全世界提供疫苗。一旦我們對於現在的工作進展更加明朗，世界衛生組織和地方衛生部門將需要製定一個疫苗分配計劃。

Eventually, though, we’re going to scale this thing up so that everybody on the planet can get the vaccine. And then, we’ll be able to get back to normal—and to hopefully make decisions that prevent us from being in this situation ever again.

最終，我們會擴大生產規模，讓地球上每一個人都能接種疫苗。之後，我們就能恢復正常生活，並有望通過明智的決策避免再次陷入相同的困境。

It might be a bit hard to see right now, but there is a light at the end of the tunnel. We’re doing the right things to get a vaccine as quickly as possible. In the meantime, I urge you to continue following the guidelines set by your local authorities. Our ability to get through this outbreak will depend on everyone doing their part to keep each other safe.

雖然前路迷茫，但光明就在前方。我們正在採取正確的做法，從而盡快獲得有效疫苗。與此同時，我迫切期望大家能繼續遵循當地衛生部門的指導。我們能否平安度過這次疫情，取決於每個人能否各盡其責以確保自己和他人的安全。