Health Organization declaring it eradicated way back in 1980.

世界衛生組織宣稱天花在 1980 年被根除。

But, we might be close to eradicating a second disease; polio.

但是，我們可能幾乎要根除第二種疾病：小兒麻痺

Yes, the disease that brings up imagery of wheelchairs and iron lungs may soon be on

沒錯，這個疾病帶出了輪椅和鐵肺的照片，可能很快

its way out, but as of 2019, we're not there yet.

就會消失，但到了 2019，我們還沒到那一步

Polio, also known as poliomyelitis, is an infectious disease caused by the aptly-named

小兒麻痺，又叫脊髓灰質炎，是一種傳染性疾病

poliovirus, which comes in three strains, and is spread mostly by consuming contaminated water.

由脊髓灰質炎病毒所造成，總共有三種類型，主要透過受汙染的飲用水散播

And by contaminated we mean, well…

受汙染的意思就是，嗯......

So, the kid poops it out, the virus gets in the water around there, usually in the sewage.

就是，小孩大便完，病毒就進入附近的水中，通常是在汙水中

And then, sometime in the next day or two or three or a week or something, some other

接著，隔天、或是兩三天，甚至是一個禮拜後的某個時候，其他小孩

kid will drink the sewage and it'll get in that kid and they'll cycle around like that.

會喝下汙水，這樣會進入小孩體內，然後他們就像這樣循環下去

Hi, I'm Jay Wenger, I'm the Director of Polio at the Bill & Melinda Gates Foundation.

嗨，我是 Jay Wenger，我是比爾與美琳達．蓋茲基金會小兒麻痺的主任

I started working on polio eradication in 2002, when I went to India, and I joined the

我在 2002 年開始從事根除小兒麻痺，當時到了印度

Gates Foundation in 2011, and have been there ever since.

我在 2011 年加入了蓋茲基金會，從那時就一直在那工作

Polio can be passed through the air with oral fluids, like from a cough or a sneeze, but

小兒麻痺可以利用口腔液體在空氣傳播，像是咳嗽或是噴嚏

the cycle today usually begins with fecal oral transmission, mostly in areas with poor sanitation.

但現今的循環通常是靠糞口路徑，主要在衛生條件差的地區

Once swallowed the virus heads straight to your intestines, finding places to replicate along the way.

一旦吞下病毒，病毒會直接進入腸道，找到可以沿路複製的地方

Now, most of the time your body will take care of the invader with an immune response,

目前，大多時候你的身體會對入侵者起免疫反應

giving you flu-like symptoms or no symptoms at all.

帶來類流感的症狀或根本沒有任何症狀

There are two things that happen with a natural infection.

自然感染會發生兩件事

Well, there are lots of things that happen, but the two main ones are, you develop humoral antibodies.

有很多事情會發生，但主要的兩個是，你會發展出體液性抗體

And those are antibodies that float around your bloodstream.

它們是漂浮在血液周圍的抗體。

And basically will, if the virus gets into your bloodstream, they'll attack it and you'll end up ejecting it.

基本上，如果病毒進入血液，它們會攻擊病毒，最後把它趕出去

The second way is producing mucosal antibodies that are secreted in the gut to ensure it doesn't reproduce.

第二種方法是產生在腸道中分泌的黏膜抗體，以確保其不會複製

But if those antibodies in the blood don't stop the infection, it could result in paralysis,

但如果身體的那些抗體沒能阻止感染，就會導致癱瘓

which occurs in about one out of every 200 people who contract the poliovirus.

感染脊髓灰質炎病毒的每 200 人中就會有 1 人癱瘓

That's because if the virus survives into your bloodstream, they can find a way into

那是因為如果病毒在血液中存活，它們可以找到

your nervous system and eventually get into the anterior horn cells of your spinal cord.

進入神經系統的方法，最後進入脊髓的角質細胞

Basically, they reproduce then they go into the cell and they reproduce

基本上，它們會再生，然後它們進入細胞並在那裡繁殖

there, and they result in death of the actual anterior horn cell, and

導致前面角質細胞的死亡

is that cell that the message from the brain transmits to the muscle.

它是從大腦傳遞給肌肉訊息的細胞

And it causes an irreversible cell death.

而且造成不可逆的細胞死亡

So, if these anterior horn cells die, it disrupts the transmission between the brain and the muscles,

因此，如果這些前角細胞死亡，就會擾亂大腦和肌肉間的傳送

such as the muscles in the torso, limbs, and between our ribs.

例如軀幹、四肢和肋骨之間的肌肉

And which part of the body becomes paralyzed will depend on which cells die.

身體哪個部位癱瘓取決於哪些細胞死亡

But, for instance, if it attacks the nerves that ultimately go to the leg, say, the right

但例如，如果它攻擊最終會進入腿部的神經，比方說右腳

leg, it can kill those nerves, and then, messages from the brain to the leg don't get there anymore.

它可以殺死那些神經，然後，從大腦到腿部的訊息就不再傳到那裡。

And so, the leg will be paralyzed, you won't be able to move it.

因此腿部會癱瘓，就沒辦法動了

That usually happens pretty quickly, usually within a day.

這通常發生得很快，通常在一天內

But, if the virus gets to the nerves that influence your breathing muscles, that's especially

但是，如果病毒到達影響呼吸肌肉的神經

bad, because you then can't breathe and your lungs don't work.

那就更糟了，因為你不能呼吸，肺也不會運作

Weakened lungs could result in death, or in some cases, bringing in a machine to help

肺部虛弱可能會導致死亡，或在某些情況下，會利用機器幫助

the patient breathe, like the iron lung

患者呼吸，像是鐵肺

All of these effects of polio; weakened lungs, paralysis and death, are why so many people

小兒麻痺的這些所有影響：虛弱的肺、癱瘓和死亡，就是為何這麼多人

are still focused on eradicating the disease.

仍致力於根除這種疾病

Polio was a huge deal in the United States. It was actually the most feared infectious

小兒麻痺在美國是個大麻煩，事實上是美國在

disease of like the 40s and 50s in the United States.

40 和 50 年代最令人恐懼的傳染病

So, there was a huge push to develop a polio vaccine.

因此，開發小兒麻痺疫苗有很大的推動力

And the first polio vaccine that got developed was developed by Salk, and that was based

第一種小兒麻痺疫苗是由沙克所開發

on a killed poliovirus preparation.

其為基於殺死小兒麻痺病毒的製劑

And so, that one was great, it was a breakthrough of its time.

所以，那個很棒，這是當時的大突破

And if you inject killed poliovirus, what you get are the humoral antibodies.

如果你注射殺死小兒麻痺病毒的疫苗，你注射的是體液性抗體

This boost of humoral antibodies in the blood helps lower the chance that the virus will

血液中體液性抗體的增加有助於降低病毒

get to your spine, reducing the risk of polio-induced paralysis.

進入脊柱的機會，降低小兒麻痺病毒引起的癱瘓風險

And so, the vaccine is good in that it prevents paralysis, and it has a little bit of an impact on the amount that you excrete.

因此，疫苗很好，因為它可以預防麻痺，而且它對你分泌量有一點影響。

It reduces it a little bit, but not a lot.

它會減少一點分泌量，但不多

So that, especially in tropical countries with rotten sanitation, the IPV is not actually

因此，特別是在衛生條件惡劣的熱帶國家，IPV 其實

a good tool to get rid of the virus from a population.

不是讓民眾擺脫病毒的好工具

That's because the IPV isn't as effective at boosting the mucosal antibodies, so the

這是因為 IPV 在增加粘膜抗體方面的效果不佳

virus still reproduces in the gut, ensuring large numbers are still passed on through poop into water supplies.

因此病毒仍會在腸道中在複製，確保大量病毒仍會透過糞便來進入供水系統

But a couple years later, Sabin came out with an oral vaccine.

但過了幾年，沙賓開發出口服疫苗

This Sabin vaccine was developed using live, weakened strains of poliovirus and helped

這種沙賓疫苗是由活性、弱化的小兒麻痺病毒所開發，不僅有助於

not only trigger humoral antibodies to protect from paralysis, but also mucosal antibodies,

引發體液性抗體來防止癱瘓，還有助於黏膜液體

which greatly reduces the amount of poliovirus passed on through poop.

明顯減少透過糞便傳播的小兒麻痺病毒數量

So, it was a huge difference and people found that soon that after using that in populations,

所以說，這是一個很大的差異，大家很快就發現，接著大家就開始使用

giving every kid in the population the OPV, a couple times, you would actually drive the wild virus away.

讓每個孩子使用 OPV 幾次，其實就可以把可怕的病毒趕走

This happened in Latin America and wild poliovirus was eventually eliminated from the

這種情況發生在拉丁美洲，可怕的小兒麻痺病毒最終

entire Americas, and then in Europe and Eastern Asia which essentially became wild poliovirus free.

從整個美洲消失，然後基本上從歐洲和東亞消失

But things sort of got slowed down a little bit in the 2000s, when we got down to like four countries.

但是在 2000 年左右，行動有點緩和下來了，我們著手處理四個國家

And that was India, Pakistan, Afghanistan and Nigeria.

有印度、巴基斯坦、阿富汗、奈及利亞

And we think that we are making progress toward finishing off polio in these last places.

而且我們認為在根除小兒麻痺方面，我們在最後幾個地方取得了進展。

India had their last case in 2011, we're hoping Nigeria had their last case in 2016.

印度最後一例是在 2011 年，我們希望奈及利亞的最後一例是在 2016 年

And we're down to only two countries right now, Afghanistan and Pakistan.

而我們現在要處理兩個國家：阿富汗和巴基斯坦

If we get rid of the wild poliovirus there, it won't be anywhere else, there's nowhere else to be.

如果我們能在那裡擺脫可怕的小兒麻痺病毒，其他地方也不會有了，任何地方都不會有

And so that will basically stop that as a cause of paralysis for kids everywhere.

因此，這基本上是阻止各地兒童癱瘓的目標