We know now that it's caused by a related virus, called vaccinia, remember the virus that causes smallpox is called variola.
我们现在知道这病由一种相关的病毒引起,这种病毒叫牛痘病毒,想想天花病毒也被叫做牛痘病毒
So, not just a spectrum of viruses, but there's viruses and bacteria and parasites and other microorganisms that can cause disease.
所以,不是只有病毒,还有病毒,细菌,寄生虫,和其它各种微生物都能导致疾病
In fact, a real powerful virus would skip the respiratory system altogether, even better than a cold virus.
事实上,真正强有力的病毒,会跳过呼吸系统,比感冒病毒好的多。
So, that was a naturally occurring attenuated virus that could be produced into a vaccine that didn't cause the disease.
因为天花病毒存在天然的衰减病毒,这种衰减病毒可以用来,直接生产不致病的疫苗
The virus is not killed so It's a live virus, which is actually going to infect your intestinal system and reproduce.
病毒没有被杀死,那么它就是活性病毒,也就意味着它将会,侵入你的肠道系统并且会繁殖
The cells would be basically little reactors for generating lots of virus so you could make lots of virus to study.
这些细胞会变成增殖反应堆,从而产生大量病毒,由此可以得到大量供研究的病毒
You would first get exposed in children-- in childhood and then at a point when you're susceptible to the disease.
在儿童期这个较容易受病毒感染时期,第一次接触该病毒,就会引起发病
Hepatitis is a virus that specifically affects the liver, so viruses are often specific to certain kinds of cells.
肝炎病毒就可以特异性的感染肝细胞,因病毒通常都有细胞特异性
They found that certain cells, in particular, epithelial cells from monkey kidneys, were very effective at propagating the virus.
他们发现有些细胞,尤其是在猴肾脏的上皮细胞中,这种病毒能够有效地增殖
Retroviruses, for example, can only insert - can only transduce and express their DNA in cells that are dividing.
就以逆转录病毒为例,它们只能在分裂阶段的细胞里,转导并表达自己的基因
Like we talked about with insulin; make large quantities of this recombinant viral protein, and use that as a vaccine.
就像我们讲过的胰岛素,生成大量重组的病毒蛋白,并将其作为疫苗使用
That's important, too, because you need to be able to tell if the virus is present in the human population.
这一点也非常重要,因为你要能够分辨出,人群中是否有人感染了天花病毒
If you just introduced this polio virus, which you could make in large quantities into people now, you would be causing polio.
如果你直接接种脊髓灰质炎病毒,将大量的病毒直接接种到人体,就会引起小儿麻痹症
The government, after this time, did issue contracts to manufacturing companies to produce new quantities of the virus.
在此事件之后,美国政府,和病毒生产企业签了,生产一些病毒的合同
AIDS is a tremendous problem, deaths from HIV infection and AIDS a tremendous problem in Africa and other parts of the world.
艾滋病是一个巨大的问题,在非洲和世界其他地方,艾滋病毒感染和艾滋病带来的死亡,是一个巨大的问题
And so even people that got vaccinated, most of us either have questionable or no protection against the virus at this point.
所以就算那些接种过天花疫苗的人,到那时候也不一定,或者压根无法抵御病毒
You would have this initial response, now that initial response might be too slow to prevent you from getting chickenpox.
你对水痘病毒产生初始应答,这种初始应答可能,过于缓慢,无法预防水痘
It's really just the result of the virus dividing within cells of your skin, and producing a lot of dead cells.
这便是病毒在皮肤细胞内部,分裂的结果,这个过程会产生大量的死亡细胞
If you can genetically engineer viruses like this and viruses have all those good properties as gene therapy vehicles that I described.
如果你能像我说的这样在遗传上改造病毒,加之病毒具备诸多优点,适合作为基因治疗的载体
So, this is a cell that's infected with a microorganism, it's infected with a virus, let's say it's infected with influenza virus.
这是一个感染了微生物的细胞,它感染了一种病毒,就说是感染了流感病毒吧
But unlike the Cowpox virus, vaccinea, that we talked about before, this is the real disease causing agent.
但是同我们之前曾讨论过的,牛痘病毒疫苗的不同之处在于,这是可以直接致病的病毒
They also found some stockpiles of the virus from the 1950s that they still had on an Army base in Maryland,I think.
政府也在马里兰军队驻地发现了,从十九世纪五十年代储存到现在的病毒
What if you're talking about a group of people that don't have any cows in their vicinity, let alone a sick cow?
万一你遇到一群人,他们附近连头奶牛都没有,更不用说受病毒感染的奶牛
But because of the similarity of the viruses, the immune response that people developed would also protect them against natural infections with variola.
因为这两种病毒很相像,人体的免疫应答也能保护自己,免受天花的感染
So, some of these cases were probably due to polio that was transmitted by incompletely killed virus that was present in the vaccine.
因此,那些病例的发病的原因,是被那些疫苗中携带的,没有被完全杀死的病毒感染
Maybe you don't need the whole virus, but you could just use a piece of the virus,right?
也许你并不需要完整的病毒,你只需使用病毒的一部分
Children get diseases from a class of viruses called rotaviruses, for which we have no vaccine, and- and so no way to protect them.
儿童因轮状病毒而生病,而我们没有针对这种病毒的疫苗,所以,所以我们没有办法保护儿童
They basically make many, many copies of their DNA and they make all of their viral proteins and they assemble into new viral units.
它们会生成不计其数的病毒基因拷贝,并翻译生成病毒蛋白,组装成新的病毒单位
So, Hepatitis is already infecting cells of their liver, their liver is actively making new virus.
乙肝病毒已经感染了他们的肝细胞,他们的肝脏正在迅速地产生新的病毒
You infect them with the virus, and you let the cells, in culture, produce the virus.
再用病毒感染它们,使培养基中的细胞产生病毒
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