本文轉自：英語世界
4月24日，比爾·蓋茨發佈長文，分享了他對全球新冠肺炎疫情的系統思考。他將新冠肺炎疫情稱為“1號當代大流行病”（The First Modern Pandemic），即現代社會第一場真正意義上的大流行病，認為此次疫情將重新定義這個時代。
蓋茨表示，目前沒有特效藥，人們恢復正常生活只能靠疫苗。新疫苗推向市場通常需要五年的時間。對於常被問及大規模疫苗接種何時可以開始，蓋茨表示可能需要18個月，也可能短至9個月或長至近2年。
Vaccines have saved more lives than any other tool in history. Smallpox, which used to kill millions of people every year, was eradicated with a vaccine. New vaccines have played a key role in reducing childhood deaths from 10 million per year in 2000 to fewer than 5 million per year today.
疫苗挽救的生命比歷史上任何其他工具都多。曾經造成每年數百萬人死亡的天花，已經被疫苗被根除。新開發的疫苗在減少兒童死亡人數方面發揮了關鍵作用，使兒童死亡人數從2000年的每年1000萬減少到今天的每年不到500萬。
Short of a miracle treatment, which we can’t count on, the only way to return the world to where it was before COVID-19 showed up is a highly effective vaccine that prevents the disease.
我們不能寄希望於某種還未研製出的神奇療法。要想讓世界恢復到新冠肺炎出現之前的狀態，唯一的辦法就是用高效的疫苗來預防這種疾病。
Unfortunately, the typical development time for a vaccine against a new disease is over five years. This is broken down into:
遺憾的是，針對一種新疾病的疫苗開發通常需要5年以上。這個流程可以被細分為：
a) making the candidate vaccine;
b) testing it in animals;
c) safety testing in small numbers of people (this is known as phase 1);
d) safety and efficacy testing in medium numbers (phase 2);
e) safety and efficacy testingin large numbers (phase 3);
f) final regulatory approval and building manufacturing while registering the vaccine in every country
a) 研製候選疫苗；
b) 進行動物試驗；
c) 對小規模人群進行安全試驗（I期臨床試驗）；
d) 對中等規模人群進行安全和有效性試驗（II期臨床試驗）；
e) 對大規模人群進行安全和有效性試驗（III期臨床試驗）；
f) 在各國進行疫苗註冊並獲得通過，然後生產建設。
Researchers can save time by compressing the clinical safety/efficacy phases while conducting animal tests and building manufacturing capacity in parallel. Even so, no one knows in advance which vaccine approach will work, so a number of them need to be funded so they can advance at full speed. Many of the vaccine approaches will fail because they won’t generate a strong enough immune response to provide protection. Scientists will get a sense of this within three months of testing in humans by looking at the antibody generation. Of particular interest is whether the vaccine will protect older people, whose immune systems don’t respond as well to vaccines.
通過做臨床安全及有效性試驗的同時開展動物試驗以及產能建設，研究人員可以從中節省一些時間。即便如此，沒有人能提前知道哪種疫苗方法會有效，所以我們需要資助若干疫苗開發，以便它們都能夠全速推進。許多疫苗最終都會失敗，因為它們無法產生足夠強大的免疫反應保護人體。通過觀察抗體的產生，科學家們預計將在人體測試後的三個月內得到答案。特別值得關注的是，疫苗是否能夠保護老年人，因為他們的免疫系統對疫苗的反應並不是很理想。
The issue of safety is obviously very important. Regulators are very stringent about safety, to avoid side effects and also to protect the reputation of vaccines broadly, since if one has significant problems, people will become more hesitant to take any vaccines. Regulators worldwide will have to work together to decide how large the safety database needs to be to approve a COVID vaccine.
安全問題顯然是非常重要的。監管機構對於疫苗的安全性要求非常嚴格，一方面是為了避免副作用，另一方面也是為了廣泛地保護疫苗的聲譽。因為如果一個疫苗出現重大問題，人們就會因此對任何免疫接種都更猶豫不決。世界各地的監管機構將需要共同努力以決定需要多少安全性數據才能批准新冠肺炎疫苗。
One step that was taken after the foundation and others called for investments in pandemic preparedness in 2015 was the creation of the Coalition for Epidemic Preparedness Innovations (CEPI). Although the resources were quite modest, they have helped advance new approaches to making vaccines that could be used for this pandemic. CEPI added resources to work on an approach called RNA vaccines, which our foundation had been supporting for some time. Three companies are pursuing this approach. The first vaccine to start human trials is an RNA vaccine from Moderna, which started a phase 1 clinical safety evaluation in March.
蓋茨基金會和其他組織在2015年共同呼籲對大流行病防範工作進行投資，並隨後創建了流行病預防創新聯盟。雖然資源相當有限，但該聯盟幫助推進了新方法，可以用於這一次大流行病的疫苗開發。流行病預防創新聯盟正在加大投入研究RNA疫苗，這種方法一直獲得蓋茨基金會的支持。現在，有三家公司正在採用這種疫苗開發手段。第一個開始人體試驗的疫苗是來自Moderna的RNA疫苗，該疫苗於3月份開始了I期臨床安全性評估。
An RNA vaccine is significantly different from a conventional vaccine. A flu shot, for example, contains bits of the flu virus that your body’s immune system learns to attack. This is what gives you immunity. With an RNA vaccine, rather than injecting fragments of the virus, you give the body the genetic code needed to produce lots of copies of these fragments. When the immune system sees the viral fragments, it learns how to attack them. An RNA vaccine essentially turns your body into its own vaccine manufacturing unit.
RNA疫苗與傳統疫苗有顯著差異。例如，流感疫苗中含有少量流感病毒，而人體的免疫系統會學會攻擊這些病毒，這就是人體獲得免疫的方法。RNA疫苗並非注射病毒片段，而是給身體提供產生大量病毒片段副本所需的遺傳密碼。當免疫系統看到這些病毒片段，它會學習如何攻擊它們。RNA疫苗本質上就是把人體變成自己的疫苗生產部門。
There are also at least five leading efforts that look promising and that use other approaches to teach the immune system to recognize and attack a viral infection. CEPI and our foundation will be tracking efforts from all over the world to make sure the most promising ones get resources. Once a vaccine is ready, our partner GAVI will make sure it is available even in low-income countries.
現在還有至少5種項目看起來很有希望，它們使用其他方法來“教會”免疫系統識別和攻擊病毒感染。CEPI 和蓋茨基金會將繼續跟蹤世界各地的項目，以確保最有前景的疫苗能獲得資源。一旦疫苗準備就緒，我們的合作伙伴全球疫苗免疫聯盟將確保低收入國家也能獲得疫苗。
A big challenge for vaccine trials is that the time required for the trials depends on finding trial locations where the rate of infection is fairly high. While you are setting up the trial site and getting regulatory approval, the infection rate in that location could go down. And trials have to involve a surprisingly large number of people. For example, suppose the expected rate of infection is 1 percent per year and you want to run a trial where you would expect 50 people to be infected without the vaccine. To get a result in six months, the trial would need 10,000 people in it.
疫苗試驗的一大挑戰是，試驗所需的時間取決於找到感染率高的試驗地點。而在設置試驗站點並得到監管機構批准的過程中，該地的感染率可能已經下降，而試驗需要大量的人參與。舉例來說，假設預期的感染率是每年1%，那你要開展的試驗就預期有50人在沒有接種疫苗的情況下被感染。那麼，為了在6個月內得到結果，這個試驗就需要1萬人參與。
The goal is to pick the one or two best vaccine constructs and vaccinate the entire world—that’s 7 billion doses if it is a single-dose vaccine, and 14 billion if it is a two-dose vaccine. The world will be in a rush to get them, so the scale of the manufacturing will be unprecedented and will probably have to involve multiple companies.
我們的目標是選擇一到兩種最好的疫苗，併為全世界人口進行疫苗接種——如果是單劑疫苗，那麼就需要70億劑；如果是雙劑疫苗，則需要140億劑。全世界都將爭相獲得這些疫苗，因此生產疫苗的規模將是前所未有的，很可能需要多家公司參與。
I am often asked when large-scale vaccination will start. Like America’s top public health officials, I say that it is likely to be 18 months, even though it could be as short as nine months or closer to two years. A key piece will be the length of the phase 3 trial, which is where the full safety and efficacy are determined.
我常被問及大規模疫苗接種何時可以開始。和美國高層的公共衛生官員們的估計一樣，我認為可能需要18個月，儘管也可能短至9個月或長至近2年。關鍵在於III期試驗的時長，這將充分確保安全性和有效性。
When the vaccine is first being manufactured, there will be a question of who should be vaccinated first. Ideally, there would be global agreement about who should get the vaccine first, but given how many competing interests there are, this is unlikely to happen. The governments that provide the funding, the countries where the trials are run, and the places where the pandemic is the worst will all make a case that they should get priority.
當首批疫苗被大規模生產時，將會出現一個問題：哪些人應該優先接種疫苗。理想情況下，全球應該就此達成共識。但鑑於存在太多利益衝突，這種共識不太可能達成。那些提供資金的政府、進行臨床試驗的國家，以及疫情最嚴重的地方，都會提出他們應該優先接種。
