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特朗普想尝试群体免疫,先从年轻人下手?

特朗普想尝试群体免疫,先从年轻人下手?

Sy Mukherjee 2020-10-19
靠群体免疫抗击疫情的想法是对传染病科学的误解。

多条报道称,特朗普政府为应对疫情,越来越接受“群体免疫”策略。但科学家和公共卫生专家相当不安,因为群体免疫策略备受争议,而且到底能否有效应对疫情以及随之而来的伦理问题,都很缺乏证据。

世界卫生组织总干事谭德塞公开抨击了靠群体免疫抗击疫情的想法,声称该思路的根源是对传染病科学的误解。

什么是群体免疫?

简单来说,群体免疫理论认为,如果有足够多的人产生抗体或对病原体免疫,就能够保护更容易受感染的人。只要免疫人群达到足够规模,就容易控制病毒传播。

问题在于群体免疫需要很长时间,而且要十分谨慎,不能像锤子钉钉一样对付新冠病毒之类的新病原体,毕竟人类新冠病毒的研究还在进行中。看看现成的例子吧,瑞典采用了群体免疫策略,结果惨不忍睹。

“要实现群体免疫,关键在于保护人们免受病毒侵害,而不是任由人们暴露在病毒中。”世界卫生组织的泰德罗斯在上周的虚拟会议上说。“公共卫生史上从未将群体免疫作为应对疫情的策略,更不用说应对大规模疫情。”他补充说,这么做很“不道德”。

要实现群体免疫,首先要有大量人群受感染。“具体规模因病而异。疾病传染性越强,对该病免疫以阻止传播的人口比例就要越高。”梅奥诊所表示。“举个例子,麻疹是传染性很强的疾病。据估计,必须有94%的人口免疫才能阻断传播链。”

证据已经显示,新冠病毒传染性极强,也就是说要达到群体免疫需要更高比例的人口获得免疫。

为何美国要考虑群体免疫

据报道,特朗普政府开始考虑让新冠病毒在年轻人中扩散,最终实现群体免疫。年轻人的症状一般没有高风险人群高。报道称,一群科学家联名支持,认为这是恢复经济发展和社会开放的手段,引起了白宫的注意。

大多数支持者并未公开。不过特朗普的高级科学顾问斯科特•阿特拉斯博士是主要支持者之一。支持该策略的其他医生和流行病学专家观点基本上都被科学界驳斥,被驳斥的观点当中包括群体免疫只需10%到20%的人群受感染。

批评人士称,面临全球100多年来最严重的疫情,采取如此试验可能导致数百万人死亡。当前证据,例如瑞典的案例似乎足以证明。随意接触新冠病毒与接种真正安全的疫苗并不是一回事,很可能只会引发更多的混乱和痛苦。(财富中文网)

译者:冯丰

审校:夏林

多条报道称,特朗普政府为应对疫情,越来越接受“群体免疫”策略。但科学家和公共卫生专家相当不安,因为群体免疫策略备受争议,而且到底能否有效应对疫情以及随之而来的伦理问题,都很缺乏证据。

世界卫生组织总干事谭德塞公开抨击了靠群体免疫抗击疫情的想法,声称该思路的根源是对传染病科学的误解。

什么是群体免疫?

简单来说,群体免疫理论认为,如果有足够多的人产生抗体或对病原体免疫,就能够保护更容易受感染的人。只要免疫人群达到足够规模,就容易控制病毒传播。

问题在于群体免疫需要很长时间,而且要十分谨慎,不能像锤子钉钉一样对付新冠病毒之类的新病原体,毕竟人类新冠病毒的研究还在进行中。看看现成的例子吧,瑞典采用了群体免疫策略,结果惨不忍睹。

“要实现群体免疫,关键在于保护人们免受病毒侵害,而不是任由人们暴露在病毒中。”世界卫生组织的泰德罗斯在上周的虚拟会议上说。“公共卫生史上从未将群体免疫作为应对疫情的策略,更不用说应对大规模疫情。”他补充说,这么做很“不道德”。

要实现群体免疫,首先要有大量人群受感染。“具体规模因病而异。疾病传染性越强,对该病免疫以阻止传播的人口比例就要越高。”梅奥诊所表示。“举个例子,麻疹是传染性很强的疾病。据估计,必须有94%的人口免疫才能阻断传播链。”

证据已经显示,新冠病毒传染性极强,也就是说要达到群体免疫需要更高比例的人口获得免疫。

为何美国要考虑群体免疫

据报道,特朗普政府开始考虑让新冠病毒在年轻人中扩散,最终实现群体免疫。年轻人的症状一般没有高风险人群高。报道称,一群科学家联名支持,认为这是恢复经济发展和社会开放的手段,引起了白宫的注意。

大多数支持者并未公开。不过特朗普的高级科学顾问斯科特•阿特拉斯博士是主要支持者之一。支持该策略的其他医生和流行病学专家观点基本上都被科学界驳斥,被驳斥的观点当中包括群体免疫只需10%到20%的人群受感染。

批评人士称,面临全球100多年来最严重的疫情,采取如此试验可能导致数百万人死亡。当前证据,例如瑞典的案例似乎足以证明。随意接触新冠病毒与接种真正安全的疫苗并不是一回事,很可能只会引发更多的混乱和痛苦。(财富中文网)

译者:冯丰

审校:夏林

The Trump administration is increasingly embracing a strategy of "herd immunity" to grapple with the COVID-19 pandemic, according to multiple reports. But the controversial strategy has scientists and public health experts on edge given the limited proof that it would work for this specific outbreak and the ethical concerns which accompany it.

Tedros Adhanom Ghebreyesus, director-general of the World Health Organization (WHO), has openly lambasted the idea of using herd immunity to fight a pandemic, asserting that it's driven by a misunderstanding of the science of infectious diseases.

What is herd immunity?

To put it simply, herd immunity is the scientific theory that if enough of a population builds antibodies or gains immunity against a pathogen, they can protect those who are more vulnerable to infection. With enough immune people, the spread of a virus becomes much more containable.

The trouble is that herd immunity is a process that takes time and caution. It can't be used as a hammer against a new pathogen like the coronavirus which we're still trying to understand. Just ask Sweden, which employed a herd immunity strategy and saw disastrous results.

“Herd immunity is achieved by protecting people from a virus, not by exposing them to it,” the WHO's Tedros said in a virtual town hall last week. “Never in the history of public health has herd immunity been used as a strategy for responding to an outbreak, let alone a pandemic," adding that it would be "unethical" to rely on this strategy.

Achieving herd immunity would require a massive proportion of the population to become infected. "It varies from disease to disease. The more contagious a disease is, the greater the proportion of the population that needs to be immune to the disease to stop its spread," according to the Mayo Clinic. "For example, the measles is a highly contagious illness. It's estimated that 94% of the population must be immune to interrupt the chain of transmission."

COVID has proven quite transmissible and contagious, suggesting that herd immunity would require a higher threshold of mass immunity.

Why the U.S. is considering the herd immunity approach

The Trump administration is reportedly open to the idea of letting coronavirus run amok among younger people, who generally don't become as sick as higher-risk populations, in order to achieve herd immunity. A group of scientists endorsed the idea as a means to reopening the economy and society at large and caught the White House's attention, according to the reports.

Most of the signatories to that declaration have not been made public. But Dr. Scott Atlas, a senior scientific advisor to President Trump, is one of its major proponents. Other doctors and epidemiologists who have signed on to the declaration espouse views that are largely rejected by the scientific community, including the notion that herd immunity would only require 10% to 20% of the population to be infected.

The results of such an experiment in the midst of a pandemic the likes of which the world hasn't seen in more than 100 years could result in millions of deaths, according to critics. Current evidence, such as what's already been seen in Sweden, appears to support that thesis. And willful exposure to the coronavirus wouldn't resemble an actual, safe vaccine; it could very well just breed more chaos and suffering.

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