Name: 新冠肺炎疫苗迅速研發出來的最大功成——mRNA疫苗！（How the COVID-19 vaccines were created so quickly - Kaitlyn Sadtler and Elizabeth Wayne）
Uploaded: 2021-10-09T21:01:30.000Z
Duration: 5 min 8 s

In the 20th century, most vaccines took well over a decade to research, test, and produce.

在二十世紀時，大多數的疫苗都需要遠超過十年的時間來研發、測試和製造。

But the vaccines for COVID-19 cleared the threshold for emergency use in less than 11 months.

但新冠肺炎的疫苗成功衝關，僅用了十一個月內的時間便獲得了緊急使用授權。

關係子句

The secret behind this speed is a medical technology that's been developing for decades: the mRNA vaccine.

疫苗快速完成背後的秘密，是一項已經發展了數十年的醫療技術：訊息 RNA（mRNA）疫苗。

This new treatment uses our body's existing cellular machinery to trigger an immune response, protecting us from viruses without ever experiencing an infection.

這個新療法使用我們體內細胞已有的物理結構和化學成分來觸發免疫反應，讓我們不用先受到病毒感染就能得到保護。

And in the future, this approach might be able to treat new diseases almost as quickly as they emerge.

而在未來，這個方法有可能可以在新疾病才剛出現時，就即時根治。

So how do these revolutionary vaccines work?

那這些革命性的疫苗是如何運作的呢？

The key ingredient is in the name—mRNA, or messenger ribonucleic acid, is a naturally occurring molecule that encodes the instructions for producing proteins.

其實它的名稱已經包含了其關鍵成分——mRNA，又稱訊息核糖核酸，是一種自然產生的分子，可以編寫指令來生產蛋白。

When our cells process mRNA, a part of the cell called the ribosome translates and follows these instructions to build the encoded protein.

當我們的細胞處理 mRNA 時， 細胞內稱為核醣體的一部分會對這些指令進行翻譯，並按照指示構建編碼中的蛋白。

The mRNA in these vaccines works in exactly the same way, but scientists use the molecule to safely introduce our body to a virus.

這些疫苗中的 mRNA  正是這樣運作，但科學家會利用分子來安全地把病毒引入我們的體內。

First, researchers encode trillions of mRNA molecules with the instructions for a specific viral protein.

首先，研究人員把指定病毒蛋白的指令編進數萬億的 mRNA 分子裡。

This part of the virus is harmless by itself, but helpful for training our body's immune response.

病毒蛋白本身無害，但有助於訓練我們身體的免疫反應。

Then, they inject those molecules into a nanoparticle, roughly 1,000 times smaller than the average cell.

然後，他們將這些分子注入大約比普通細胞小一千倍的奈米粒子。

This nanoparticle is made of lipids, the same type of fatty material that forms the membrane around our cells.

這種奈米粒子由脂質構成， 與我們細胞膜的脂肪物質一樣。

But these lipids have been specially engineered to protect the mRNA on its journey through the body, and assist its entry into the cell.

但這些脂質經過了特別設計來在一路上保護 mRNA，協助它進入細胞。

Lastly, the final ingredients are added: sugars and salt, to help keep the nanoparticles intact until they reach their destination.

最後要添加最終成分：糖和鹽，藉此幫助納米粒子在到達目的地前維持完整。

Before use, the vaccine is kept at a temperature of -20 to -80 degrees Celsius to ensure none of the components break down.

使用前，疫苗要保存在 -20 至 -80 攝氏度的溫度，以確保不會有任何成分分解。

Once injected, the nanoparticles disperse and encounter cells.

一經注射，奈米粒子便會分散並接觸細胞。

The lipid coating on each nanoparticle fuses with the lipid membrane of a cell and releases the mRNA to do its work.

每粒奈米顆粒上的脂質層與細胞的脂質膜相融合，繼而釋放出 mRNA 來讓它開始工作。

At this point, we should note that while the vaccine is delivering viral genetic material into our cells, it's impossible for this material to alter our DNA.

在這個時候，我們需要注意的是，雖然疫苗會將病毒遺傳物質輸送到我們的細胞中，但這種物質並不可能改變到我們的 DNA。

mRNA is a short-lived molecule that would need additional enzymes and chemical signals to even access our DNA, let alone change it.

mRNA 是一種壽命短暫的分子，需要額外的酵素和化學訊號才能存取我們的 DNA，更不用說改變它了。

And none of these DNA-altering components are present in mRNA vaccines.

再者，這些能改變 DNA 的成分都不存在於 mRNA 疫苗中。

Once inside the cell, the ribosome translates the mRNA's instructions and begins assembling the viral protein.

一旦進入細胞， 核醣體就會翻譯 mRNA 的指令，並開始組裝病毒蛋白。

In COVID-19 vaccines, that protein is one of the spikes typically found on the virus's surface.

在新冠肺炎的疫苗中，這種蛋白就是通常在病毒表面發現的尖刺之一。

Without the rest of the virus, this lone spike is not infectious, but it does trigger our immune response.

少了病毒的其餘部分，這段尖刺雖然沒有傳染力，卻能觸發我們的免疫反應。

Activating the immune system can be taxing on the body, resulting in brief fatigue, fever, and muscle soreness in some people.

免疫系統被觸發後會對身體造成負擔，有些人身上會出現短暫的疲勞、發燒和肌肉酸痛的症狀。

But this doesn't mean the recipient is sick—it means the vaccine is working.

但這並不代表接種者生病了——這是代表疫苗正在發揮作用。

The body is producing antibodies to fight that viral protein, that will then stick around to defend against future COVID-19 infections.

身體會產生抗體來對抗這種病毒蛋白，然後抗體會繼續待在體內，抵禦未來新冠肺炎的感染。

And since this particular protein is likely to be found in most COVID variants, these antibodies should reduce the threat of catching new strains.

由於在大多數的新冠病毒變體中都很有可能有這種特殊的蛋白，這些抗體便能降低感染新株的威脅。

This approach offers significant advantages over previous vaccines.

這種方法與過去的疫苗相比有著明顯的優勢。

Traditional vaccines contain weakened versions of live viruses or amputated sections of a virus, both of which required time-intensive research to prepare and unique chemical treatments to safely inject.

傳統疫苗中含有活性被減低的病毒或病毒的部分結構，而這兩者都需要長時間的研究來準備，亦需要獨特的化學處理才能安全注射。

But mRNA vaccines don't actually contain any viral particles, so they don't have to be built from scratch to safely adjust each virus.

但 mRNA 疫苗並沒有內含任何真正的病毒粒子，因此不需為了每種病毒安全地作出調整而從頭構建。

In fact, every mRNA vaccine could have roughly the same list of ingredients.

事實上， 每種 mRNA 疫苗的成分都大致相同。

Imagine a reliable, robustly tested vaccine that can treat any disease by swapping out a single component.

想像一種可靠、經過嚴格測試的疫苗，可以通過更換單個成分來治療任何疾病。

To treat a new illness, researchers would identify the right viral protein, encode it into mRNA, and then swap that mRNA into the existing vaccine platform.

要治療一種新疾病，研究人員會識別正確的病毒蛋白，將其編碼為 mRNA，然後把該 mRNA 注入到疫苗平台中，替代現有的 mRNA。

This could make it possible to develop new vaccines in weeks, giving humanity a flexible new tool in the never-ending fight against disease.

這技術可讓新疫苗能夠在數週內開發完成，給予人類在與疾病永無止境的對抗中，一種靈活的新工具。

But where do vaccines get started? Watch this video to travel back to 1796, when an eight-year-old boy changed the course of history.

但疫苗最早是怎麼發明出來的？觀看這部回到 1796 年的影片，瞭解一位當時才八歲的小男孩是怎麼改變歷史的。

Or, get the answer to a pressing question: When exactly is a pandemic over?

或者獲得對一個逐漸迫近的問題的解答：疫情到底要到什麼時候才算是結束？