Name: 為什麼不能拿新冠肺炎疫苗做比較？ (Why you can't compare Covid-19 vaccines)
Uploaded: 2021-03-20T18:10:31.000Z
Duration: 7 min 2 s

This is the new one-dose Covid-19 vaccine from Johnson & Johnson.

這是嬌生公司所新推出的單劑型Covid-19疫苗

基礎被動語態

were supposed to be shipped to the city of Detroit, Michigan.

本來是要運到密西根州底特律市的

to make sure the residents of the city of Detroit get the best."

以確保底特律市民得到最好的。」

He was referring to these numbers: the vaccines' "efficacy rates."

他指的是這些數字：疫苗的 「效能」

The vaccines from Pfizer/BioNTech and Moderna have super high efficacy rates:

輝瑞/BNT和莫德納的疫苗具有超高的效能

And if you only look at these numbers, it's natural to think that these vaccines

單看這些數字，你自然而然地認為這些疫苗

These numbers are arguably not even the most important measure

To understand what is, you first have to understand what vaccines are even supposed to do.

該拿什麼來衡量，首先要了解到底疫苗的功用是什麼

A vaccine's efficacy rate is calculated in large clinical trials,

疫苗的效能是通過大型臨床試驗計算出來的

when the vaccine is tested on tens of thousands of people.

當疫苗在數以萬計的人身上測試時

half get the vaccine, and half get a placebo.

Then, they're sent out to live their lives,

然後，他們被送回家正常過生活

while scientists monitor whether or not they get Covid-19 over several months.

而科學家們在幾個月內監測他們是否感染了 Covid-19

In the trial for Pfizer/BioNTech, for example, there were 43,000 participants.

以輝瑞/BNT的試驗為例，在43,000名參與者中

In the end, 170 people were infected with Covid-19.

And how those people fall into each of these groups determines a vaccine's efficacy.

而這些感染者在兩個組別中的比例，決定了疫苗的效能

如果這170人平分散落於兩組的話

that would mean you're just as likely to get sick with the vaccine as without it.

就意味著打不打疫苗都一樣容易生病

If all 170 were in the placebo group, and zero people who got the vaccine were sick,

如果170人都在安慰劑組，而打了疫苗的人沒人得病

the vaccine would have an efficacy of 100%.

With this particular trial, there were 162 in the placebo group,

假設在這項試驗中，安慰劑組有162人得病

It means those who had the vaccine were 95% less likely to get Covid-19:

那就意味著那些接種了疫苗的人感染Covid-19的可能性降低了95%。

Now, this doesn't mean that if 100 people are vaccinated, 5 of them will get sick.

這並不是指每100個人接種了疫苗，就有5個人會生病

Instead, that 95% number applies to the individual.

相反的，這95%的數字是針對個人

So, each vaccinated person is 95% less likely than a person without a vaccine

所以，每個接種過疫苗的人在每次接觸Covid-19時

to get sick, each time they're exposed to Covid-19.

比沒有接種過疫苗的人少了95%得病的可能性

And every vaccine's efficacy rate is calculated in the same way.

而每一種疫苗的效能都是以同樣的方式計算的

But each vaccine's trial might be done in very different circumstances.

然而每種疫苗的臨床試驗情況不盡相同

"So, one of the biggest considerations here, when we look at these numbers,

「所以，當我們在看這些數據的時候，最重要的一點

is the timing in which these clinical trials were performed."

是這些臨床試驗進行的時間點。」

This is the number of daily Covid-19 cases in the US since the pandemic began.

這是美國自疫情開始以來，每天的Covid-19確診人數

The Moderna trial was done completely in the US,  here, in the summer.

莫德納的臨床試驗完全在夏日的美國完成的

The Pfizer/BioNTech trial was primarily based in the US, too, and at the same time.

同一時間，輝瑞/BNT的臨床試驗主要也是在美國進行

Johnson & Johnson, however, held their US trial at this time,

然而，嬌生公司在美國的臨床試驗，卻是在不同時候進行的

when there were more opportunities for participants to be exposed to infections.

此時的參與者接觸到病毒的機會更高

And most of their trial took place in other countries, primarily South Africa and Brazil.

而且他們的臨床試驗大多在其他國家進行，主要在南非和巴西

And in these other countries, not only were case rates high,

The trials took place as variants of Covid-19 emerged,

臨床試驗是在Covid-19出現變異種的時候進行的

and became the dominant infections in these countries;

而變種病毒正在這些國家(南非、巴西)肆虐

variants that are more likely  to get participants sick.

變種病毒本身就更容易讓試驗參與者生病

In South Africa, most of the cases in the Johnson & Johnson trial were that of the variant,

在南非，嬌生公司臨床試驗的大部分病例，都是感染變種病毒

not the original strain that was in the US over the summer.

與美國在夏季的病毒就不一樣了

And despite that, it still significantly reduced infections.

儘管如此，疫苗還是大大降低了傳染率

"If you're trying to make one-to-one,  head-to-head comparisons between vaccines,

they need to have been studied in the same trial, with the same inclusion criteria,

它們必須在同一臨床試驗中進行研究，並採用相同的收案標準

in the same parts of the world, at the same time."

在同一個地區，在同一時間。」

"If we were to take Pfizer and Moderna's vaccines,

「如果我們在嬌生疫苗臨床試驗的同一時間

and redo their clinical trial at the same time that we saw J&J's clinical trial,

重新對輝瑞和莫德納的疫苗進行臨床試驗

we might see quite different efficacy numbers for those."

我們可能會看到完全不同的效能結果。」

These efficacy numbers really just tell you what happened in each vaccine's trial,

這些效能的數字僅告訴你每個疫苗在該臨床試驗中的結果

not exactly what will happen in the real world.

但並不代表現實世界的效價也是如此

But many experts argue this isn't even the best number to judge a vaccine by anyway.

很多專家認為，無論如何這都不是評斷疫苗的最佳指標

Because preventing any infection at all is not always the point of a vaccine.

因為預防所有的感染並非總是疫苗的目的

"The goal of a vaccine program for Covid-19 is not necessarily to get to 'Covid zero,'

「Covid-19疫苗計劃的目標並不是要把感染率降到零

but it's to tame this virus, to defang it,

而是要削弱這隻病毒，並解除它的威脅

to remove its ability to cause serious disease, hospitalization, and death."

讓它無法導致患者出現重症、住院甚至死亡。」

It helps to look at the different outcomes of an exposure to Covid-19 like this:

綜觀感染Covid-19後的各種結局：

The best-case scenario is, you don't get sick at all.

最好的情況是，你根本不會得病

In between, there's being hospitalized, severe-to-moderate symptoms,

在中間則有住院、重度到輕度的症狀

In the absolute best circumstances, vaccines give you protection all the way to here.

在最好的情況下，疫苗給你的全面的保護

But realistically, that isn't the main objective of Covid-19 vaccines.

但現實上，這並不是Covid-19疫苗的主要目的

The real purpose is to give your body enough protection to cover these possibilities,

真正的目的是給你的身體提供足夠的保護，來應付這些症狀

so if you do get an infection, it feels more like a cold

假使你真的中了，會有類似感冒的症狀

than something you'd be hospitalized for.

And this is one thing that every one of these Covid-19 vaccines do well.

而這也是每一種Covid-19疫苗都能做到的事

In all these trials, while some people in the placebo groups were hospitalized,

在所有臨床試驗中，當安慰劑組中某些感染COVID-19的人需要住院

not one fully vaccinated person, in any of these trials,

在每一個臨床試驗中完整接種過疫苗的人

沒有人因為感染Covid-19而住院或死亡

"One thing that I wish that mayor would have understood,

was that all three vaccines have essentially 100% effectiveness in protecting from death."

這三種疫苗基本上百分之百避免了死亡。」

The mayor of Detroit did backtrack, and said he'd start taking Johnson & Johnson doses,

底特律市長也確實改變了過去的主張，他說他會開始使用嬌生公司的疫苗

because it's still "highly effective against what we care about most."

因為它非常有效地避免了我們最擔心的事情

Efficacy matters. But it doesn't matter the most.

效能固然重要，但並不是最重要的

The question isn't which vaccine will protect you from any Covid infection,

問題不在於哪種疫苗能保護你免受Covid-19的感染

"The best vaccine right now for you is the one that you're offered."

「最好的疫苗就是現在你能施打到的那一種。」

"With each shot that goes into someone's arm, we get closer to the end of this pandemic."

「當每一針打進某人的手臂，我們就更接近疫情的終點。」