地平线系列：冠状病毒特别节目（2020）（2）

two candidate coronavirus vaccines are safe for use in humans.
这意味着疫苗要先在动物身上做测试
And that meant trialling the vaccines on animals first.
我们开始对猕猴和雪貂
We have started vaccinating macaques and ferrets
迈尔斯·卡罗尔教授
英国公共卫♥生♥部♥门
接种候选疫苗
with candidate vaccines.
接种后等待一段时间
Wait a certain amount of time after vaccination
然后再给它们注射一已知量的病毒
and we challenge it with a known amount of virus.
未经授权 禁止进入
生物危害警告
动物们会被暴露在病毒中
Animals are challenged by exposing them to the virus,
然后对它们进行评估
then they're evaluated.
我们找的是接种动物和未接种动物之间的差异
We look for differences between the vaccinated animals
想借此验证 第一 疫苗有效
and the unvaccinated animals, to show, A, the vaccine has worked,
第二 也是更为重要的 处理潜在安全问题
but importantly, B, to address any safety concerns.
确保公众对疫苗的安全性充满信心
The need to ensure the public can be confident
这一需求
that vaccines are safe
在1976年美国发生的一件大事中尤为突出
is highlighted by events in America, in 1976.
没人知道这个威胁究竟有多严重
No one knows exactly how serious this threat could be.
这个国家面临致命的新型猪流感病毒爆发危机
The country faced an outbreak of a deadly new swine flu virus.
我要求每一位美国人
I am asking each and every American
无论男女 都要确保
to make certain he or she receives
在这个秋季进行预防接种
an inoculation this fall.
四千万美国人都进行了预防接种
40 million Americans were vaccinated.
一小部分人出现了
A small number of people developed
一种罕见的神经疾病
a rare neurological condition called
称为吉兰巴雷综合征 这种病可能会导致瘫痪
Guillain-Barre syndrome, which can lead to paralysis.
研究表明接受预防接种的人
Research showed those who were vaccinated
会增加小部分患吉兰巴雷综合征的风险
had a small increased risk of developing GBS.
这种联♥系♥的确切原因至今仍未发现
The exact reason for this link remains unknown.
然而公众对疫苗的信心大受动摇
Nevertheless, public confidence in vaccines were shaken,
这也表明为什么稳健的安全性测试至关重要
showing why robust safety trials are vital,
即使我们处在疾病爆发的关键时期
even in the middle of an outbreak.
在波顿登研究基地 安全性测试的一个关注点是
At Porton Down, one focus of the safety trials is making sure
确保疫苗不会引发罕见的免疫系统并发症
a vaccine does not lead to rare immune system complications,
并导致个体暴露在病毒中之后 产生严重疾病
that can cause serious disease, after exposure to the virus.
通过同一种类的疫苗SARS-1
With a related vaccine SARS-1,
在动物实验体上的实例
in some instances in animal models,
我们确实可以发现病毒在增强
there was an indication that you did see enhanced disease.
它们跟我们现在所测试的疫苗
They were different types of vaccines
是不同的类型
that we are testing here today.
测试动物将会被检查肺部
Animals in the trial will have their lungs checked
是否有受损
for possible damage.
使用了COVID-19疫苗之后
With the COVID-19 vaccine,
有没有观察到任何不良结果
are you seeing any sort of bad things happening?
我们只对动物进行了疫苗注射
So, we have only vaccinated the animals
它们看起来都非常健康
and they look completely and utterly healthy.
在让动物暴露在病毒中之前
And we won't be able to measure any effect
我们无法测试出任何效果
until after we have challenged the animals.
那么目前 你们在动物身上测试的疫苗
So, so far, vaccines that you have been testing on animals
是安全的吗
appear to be safe?
是的 可以确定
They certainly do.
因为疫苗是给健康人接种
Because vaccines are given to healthy people,
来防止他们被感染的
to protect them from infection,
因此 确保疫苗是否安全至关重要
establishing that they are safe is paramount.
对于生命垂危的癌症病人
The risk-benefit ratio
他们的风险收益比不同
for someone dying of cancer,
你会冒险用毒药来救他们的命
you would risk giving them a toxic drug to save their lives.
但如果你要给一个健康人接种疫苗
But if you are vaccinating a healthy individual,
那你就必须确保疫苗非常安全
then you have to have something that is extremely safe
不会伤害人体
and will do no harm.
波顿登研究基地所测试的冠状病毒疫苗中
One of the candidate coronavirus vaccines
有一种是由牛津大学研发的
Porton Down has been testing is developed by Oxford University.
欧洲首例冠状病毒疫苗人体实验
The first human trial in Europe of a coronavirus vaccine
已在牛津大学展开
has begun in Oxford.
在美国通过疫苗安全测试后
The vaccine has been allowed to start human trials,
疫苗已被允许进行人体实验
after successful safety tests in America.
一般来说
The normal way we do this,
桑迪·道格拉斯博士
牛津大学 詹纳研究所
在考虑是否让一种疫苗投入大规模使用前
it takes several years to get to the point of having a vaccine
就会花费数年的时间
that would actually even be considered for widespread use.
现在 即使疫苗效果还不明确
And now the group is gearing up to produce
科研团队就要加紧准备生产近百万支疫苗
around a million doses of the vaccine before they know it works.
我们现在已经开始进行临床生产
We've started moving to doing real clinical manufacturing,
大规模生产 比正常提前了许多
at industrial scale, very early.
我们希望一旦临床试验证明疫苗安全有效
We want a vaccine to be ready as soon as the clinical trial shows
疫苗就能够马上就绪
that the vaccine can be safe and work in people.
但要让疫苗准备好投入大规模生产
But to have the vaccine ready then,
我们需要提前许多个月开始
we need to start months and months in advance.
我们预计 如果一切顺利
And we're hoping, if everything goes really well,
大概在初秋 我们也许能让一部分疫苗
we might have some vaccine ready to use
准备投入使用
in perhaps the early autumn.
到那时
At that point,
监管机构可能会批准该疫苗的紧急使用
regulators might grant an emergency use of the vaccine
这会使得临床测试的规模增大
that would allow the human trial to scale up
能让成千上万的人接种
to potentially vaccinate tens of thousands of people.
刚开始 接种人群会相对受限
It would be, initially, relatively restricted,
主要是给医护人员 还有给疗养院的人
health care workers, maybe people living in care homes,
还可能会给患有潜在肺部疾病的老年人
perhaps older people with underlying lung diseases.
能从疫苗中获益最大的人群
The people who have got the most to benefit from the vaccine
可能会首先接种
would likely be the first to receive this.
牛津大学的疫苗只是由世界顶级科学家
The Oxford vaccine is one of over a hundred being developed
所研发的一百多种疫苗的其中一种
by the world's leading vaccine scientists.
在过去 这些科学家专攻
And in the past they have focused on
诸如艾滋病 流感和埃博拉这样的疾病
diseases like HIV, influenza and Ebola.
现在 他们会将
And now they are bringing
研究出来的各种技术
all of those different techniques they have developed
用于攻克新型冠状病毒
to the new coronavirus.
疫苗通过刺♥激♥你的免疫系统
Vaccines work by stimulating your immune system
产生这些叫做抗体的蛋白质来起作用
to produce these proteins called antibodies,
抗体会与病毒表面结合 使其失活
that bind to the surface of a virus and neutralise it.
你所接种过的所有疫苗
All of the vaccines you've ever had
可以被分为两大类
fall into one of two broad categories.
减毒疫苗和灭活疫苗
Live ones and dead ones.
灭活疫苗最为简单
Dead vaccines are the simplest.
这种方法是通过
In this case,
实验室制♥造♥出新型冠状病毒的一种蛋白质
a protein from the new coronavirus is made in a lab
然后注射进人体
and then injected into the body.
这很安全 但通常像这样的疫苗
It is safe. But in general, vaccines like this
不会产生长久的免疫反应
do not generate such a long lasting immune response
而且通常需要再次注射
and boosters are often needed.
而其它一些科研团队正在研究另一种疫苗
The other type that a few different groups are working on
一种具有活性的疫苗
is live vaccines,
是注射减毒后的冠状病毒
a weakened form of the coronavirus itself is injected.
这种疫苗会产生强烈的免疫反应
And these vaccines create a strong immune response
而这种疫苗已被用于预防
and vaccines like this have been used for
水痘 天花 麻疹和风疹
chickenpox, smallpox, measles and rubella.
但我们通常不能将具有活性病毒的疫苗
But we often can't give live virus vaccines
给老年人 还有免疫系统弱的人
to older people and those with weak immune systems.
也就是说
In other words,
不能给感染COVID-19♥风♥险最大的人群
the very people at greatest risk of COVID-19.
现在 另外一些团队正在研究
Now dozens of other groups are working on technologies
之前从未在人体上被广泛运用的技术
which have never been used widely before in human beings.
牛津大学的团队正在使用一种
So the group of Oxford are using an approach
叫做病毒载体法的方法
called the viral vector method.
他们使用一种通常只会感染黑猩猩的病毒
They take a virus that normally infects chimpanzees.
并进行基因修改
then genetically modified
使它们不能复♥制♥和传播
so it can't reproduce or spread.
他们也会在这加入
And they also add in a gene here
新型冠状病毒的突刺蛋白基因
for the new coronavirus spike protein,
当黑猩猩病毒进入人体免疫细胞的时候
and when this chimp virus enters cells of the human immune system
会生产出冠状病毒的突刺蛋白
the coronavirus spike protein is made.
它们会到细胞的表面