How the COVID-19 vaccines were created so quickly - Kaitlyn Sadtler and Elizabeth Wayne

Translator: xu Evonne Reviewer: Thomas Tam

In the 20th century, most vaccines took well over a decade

喺二十世紀，多數嘅疫苗 需要超過十年嘅時間

to research, test, and produce.

嚟做研究、測試同埋生產

But the vaccines for COVID-19 cleared the threshold for emergency use

但 COVID-19 疫苗 只係用咗十一個月

in less than 11 months.

就緊急投入使用

The secret behind this speed is a medical technology

背後嘅秘密，係發展咗幾十年嘅

that’s been developing for decades:

一項醫療科技：

the mRNA vaccine.

mRNA 疫苗

This new treatment uses our body’s existing cellular machinery

新疫苗係運用身體現有嘅細胞機制

to trigger an immune response,

嚟觸發免疫系統反應

protecting us from viruses without ever experiencing an infection.

免除我哋受到病毒嘅侵襲同感染

And in the future, this approach might be able to treat new diseases

同時呢種方法亦有可能治療 喺未來嘅新疾病

almost as quickly as they emerge.

針對新疾病，即時產生抗體

So how do these revolutionary vaccines work?

咁革命性嘅疫苗係點樣運作嘅呢？

The key ingredient is in the name.

最顯著嘅組成部分

mRNA, or messenger ribonucleic acid, is a naturally occurring molecule

就係 mRNA， 又叫做信使核糖核酸 屬既有存在嘅份子

that encodes the instructions for producing proteins.

佢為指令編碼產生蛋白質

When our cells process mRNA, a part of the cell called the ribosome

當細胞處理 mRNA 嗰陣 裏面嘅核糖體

translates and follows these instructions to build the encoded protein.

會翻譯同跟住指令 編碼製造蛋白質

The mRNA in these vaccines works in exactly the same way,

喺疫苗度嘅 mRNA 以同樣嘅方式發生作用

but scientists use the molecule to safely introduce our body to a virus.

但科學家安全噉使用呢啲分子 為身體引入咗病毒

First, researchers encode trillions of mRNA molecules with the instructions

首先，研究人員為特定嘅病毒蛋白質

對數万億個 mRNA 分子進行編碼

for a specific viral protein.

This part of the virus is harmless by itself,

呢個部分本身係無害嘅

but helpful for training our body’s immune response.

但對訓練身體免疫系統反應產生作用

Then, they inject those molecules into a nanoparticle

然後將啲分子注入到納米粒子度

roughly 1,000 times smaller than the average cell.

佢比普通細胞大概細 1,000 倍

This nanoparticle is made of lipids,

啲納米顆粒由脂質所構成

the same type of fatty material that forms the membrane around our cells.

嗰啲脂肪類型 係同包圍住細胞嘅膜相同

But these lipids have been specially engineered

但佢哋係經過特別設計

to protect the mRNA on its journey through the body

可以保護同協助 mRNA

and assist its entry into the cell.

穿過身體進入細胞

Lastly, the final ingredients are added: sugars and salt

到最後加埋糖同鹽

幫助保存納米離子 完整噉去到目的地

to help keep the nanoparticles intact until they reach their destination.

Before use, the vaccine is kept at a temperature of -20 to -80 degrees Celsius

疫苗使用前要保存喺 攝氏 -20 到 -80 度

to ensure none of the components break down.

確保冇產生任何變質

Once injected, the nanoparticles disperse and encounter cells.

啲納米顆粒喺注入咗疫苗 就分散去尋找細胞

The lipid coating on each nanoparticle fuses with the lipid membrane of a cell

每個納米顆粒脂質塗層 同細胞脂質膜融合起來

and releases the mRNA to do its work.

同時釋放 mRNA 嚟完成工作

At this point, we should note that while the vaccine is delivering

依家需要留意嘅係 疫苗雖然喺度傳遞緊

viral genetic material into our cells,

啲病毒基因物質進入細胞

it’s impossible for this material to alter our DNA.

但佢唔可以改變我哋嘅 DNA

mRNA is a short-lived molecule

因為 mRNA 生命週期好短

that would need additional enzymes and chemical signals to even access our DNA,

佢需要加上酶同化學信號 才可以到訪我哋嘅 DNA

let alone change it.

更唔好話改變佢哋

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

喺 mRNA 疫苗度 唔會有改變 DNA 嘅成分

Once inside the cell, the ribosome translates the mRNA’s instructions

當佢進入咗細胞 核糖體翻譯 mRNA 嘅指令

and begins assembling the viral protein.

同埋開始組裝病毒蛋白

In COVID-19 vaccines, that protein is one of the spikes typically found

喺 COVID-19 疫苗度嘅蛋白質 通常喺病毒表面

on the virus’s surface.

急劇增加濃度

Without the rest of the virus this lone spike is not infectious,

但噉係冇傳染性嘅 因為佢冇咗其他病毒部分

but it does trigger our immune response.

佢確實可以觸發我哋免疫系統反應

Activating the immune system can be taxing on the body,

激活免疫系統會造成身體嘅負擔

resulting in brief fatigue, fever, and muscle soreness in some people.

導致某啲人有短暫嘅疲勞 發燒同肌肉酸痛

But this doesn’t mean the recipient is sick—

但唔係接種人受到感染跡象

it means the vaccine is working.

只係疫苗產生作用

身體產生緊抗體嚟對抗病毒蛋白

The body is producing antibodies to fight that viral protein,

that will then stick around to defend against future COVID-19 infections.

抵抗 COVID-19 嘅感染

特殊蛋白可以存在喺 大多數 COVID-19 變體度

And since this particular protein is likely to be found in most COVID variants,

these antibodies should reduce the threat of catching new strains.

可以減少新毒株感染嘅威脅

呢種方法同以前嘅疫苗相比 具有顯著嘅優勢

This approach offers significant advantages over previous vaccines.

Traditional vaccines contain weakened versions of live viruses

傳統嘅疫苗，包含弱化咗嘅活性病毒

or amputated sections of a virus,

或者刪去咗病毒嘅部分

both of which required time intensive research to prepare

兩者都需要大量時間嚟做研究同準備

and unique chemical treatments to safely inject.

同時要用獨特嘅化學 進行安全嘅注射

But mRNA vaccines don’t actually contain any viral particles,

但 mRNA 疫苗 並冇包含任何病毒顆粒

so they don’t have to be built from scratch to safely adjust each virus.

所以佢哋唔須要為每種病毒逐一調整

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

每種 mRNA 疫苗 都有大致相同嘅成分

Imagine a reliable, robustly tested vaccine that can treat any disease

想像經過嚴格測試嘅一種可靠疫苗 只需要更換一樣成分

by swapping out a single component.

就可以用嚟治療任何疾病

To treat a new illness, researchers would identify the right viral protein,

首先，研究人員會識別出 正確嘅病毒蛋白

encode it into mRNA,

然後編碼到 mRNA

and then swap that mRNA into the existing vaccine platform.

再將 mRNA 轉換到現有嘅疫苗平台

This could make it possible to develop new vaccines in weeks,

幾個星期後，就可以開發出新嘅疫苗

giving humanity a flexible new tool in the never-ending fight against disease.

提供人類喺永無止境嘅疾病鬥爭中 靈活嘅新工具