多條報道稱,特朗普政府為應對疫情,越來越接受“群體免疫”策略。但科學家和公共衛(wèi)生專家相當不安,因為群體免疫策略備受爭議,而且到底能否有效應對疫情以及隨之而來的倫理問題,都很缺乏證據。
世界衛(wèi)生組織總干事譚德塞公開抨擊了靠群體免疫抗擊疫情的想法,聲稱該思路的根源是對傳染病科學的誤解。
什么是群體免疫?
簡單來說,群體免疫理論認為,如果有足夠多的人產生抗體或對病原體免疫,就能夠保護更容易受感染的人。只要免疫人群達到足夠規(guī)模,就容易控制病毒傳播。
問題在于群體免疫需要很長時間,而且要十分謹慎,不能像錘子釘釘一樣對付新冠病毒之類的新病原體,畢竟人類新冠病毒的研究還在進行中??纯船F(xiàn)成的例子吧,瑞典采用了群體免疫策略,結果慘不忍睹。
“要實現(xiàn)群體免疫,關鍵在于保護人們免受病毒侵害,而不是任由人們暴露在病毒中?!笔澜缧l(wèi)生組織的泰德羅斯在上周的虛擬會議上說。“公共衛(wèi)生史上從未將群體免疫作為應對疫情的策略,更不用說應對大規(guī)模疫情?!彼a充說,這么做很“不道德”。
要實現(xiàn)群體免疫,首先要有大量人群受感染?!熬唧w規(guī)模因病而異。疾病傳染性越強,對該病免疫以阻止傳播的人口比例就要越高?!泵穵W診所表示?!芭e個例子,麻疹是傳染性很強的疾病。據估計,必須有94%的人口免疫才能阻斷傳播鏈?!?/p>
證據已經顯示,新冠病毒傳染性極強,也就是說要達到群體免疫需要更高比例的人口獲得免疫。
為何美國要考慮群體免疫
據報道,特朗普政府開始考慮讓新冠病毒在年輕人中擴散,最終實現(xiàn)群體免疫。年輕人的癥狀一般沒有高風險人群高。報道稱,一群科學家聯(lián)名支持,認為這是恢復經濟發(fā)展和社會開放的手段,引起了白宮的注意。
大多數支持者并未公開。不過特朗普的高級科學顧問斯科特?阿特拉斯博士是主要支持者之一。支持該策略的其他醫(yī)生和流行病學專家觀點基本上都被科學界駁斥,被駁斥的觀點當中包括群體免疫只需10%到20%的人群受感染。
批評人士稱,面臨全球100多年來最嚴重的疫情,采取如此試驗可能導致數百萬人死亡。當前證據,例如瑞典的案例似乎足以證明。隨意接觸新冠病毒與接種真正安全的疫苗并不是一回事,很可能只會引發(fā)更多的混亂和痛苦。(財富中文網)
譯者:馮豐
審校:夏林
多條報道稱,特朗普政府為應對疫情,越來越接受“群體免疫”策略。但科學家和公共衛(wèi)生專家相當不安,因為群體免疫策略備受爭議,而且到底能否有效應對疫情以及隨之而來的倫理問題,都很缺乏證據。
世界衛(wèi)生組織總干事譚德塞公開抨擊了靠群體免疫抗擊疫情的想法,聲稱該思路的根源是對傳染病科學的誤解。
什么是群體免疫?
簡單來說,群體免疫理論認為,如果有足夠多的人產生抗體或對病原體免疫,就能夠保護更容易受感染的人。只要免疫人群達到足夠規(guī)模,就容易控制病毒傳播。
問題在于群體免疫需要很長時間,而且要十分謹慎,不能像錘子釘釘一樣對付新冠病毒之類的新病原體,畢竟人類新冠病毒的研究還在進行中??纯船F(xiàn)成的例子吧,瑞典采用了群體免疫策略,結果慘不忍睹。
“要實現(xiàn)群體免疫,關鍵在于保護人們免受病毒侵害,而不是任由人們暴露在病毒中?!笔澜缧l(wèi)生組織的泰德羅斯在上周的虛擬會議上說。“公共衛(wèi)生史上從未將群體免疫作為應對疫情的策略,更不用說應對大規(guī)模疫情?!彼a充說,這么做很“不道德”。
要實現(xiàn)群體免疫,首先要有大量人群受感染?!熬唧w規(guī)模因病而異。疾病傳染性越強,對該病免疫以阻止傳播的人口比例就要越高?!泵穵W診所表示?!芭e個例子,麻疹是傳染性很強的疾病。據估計,必須有94%的人口免疫才能阻斷傳播鏈?!?/p>
證據已經顯示,新冠病毒傳染性極強,也就是說要達到群體免疫需要更高比例的人口獲得免疫。
為何美國要考慮群體免疫
據報道,特朗普政府開始考慮讓新冠病毒在年輕人中擴散,最終實現(xiàn)群體免疫。年輕人的癥狀一般沒有高風險人群高。報道稱,一群科學家聯(lián)名支持,認為這是恢復經濟發(fā)展和社會開放的手段,引起了白宮的注意。
大多數支持者并未公開。不過特朗普的高級科學顧問斯科特?阿特拉斯博士是主要支持者之一。支持該策略的其他醫(yī)生和流行病學專家觀點基本上都被科學界駁斥,被駁斥的觀點當中包括群體免疫只需10%到20%的人群受感染。
批評人士稱,面臨全球100多年來最嚴重的疫情,采取如此試驗可能導致數百萬人死亡。當前證據,例如瑞典的案例似乎足以證明。隨意接觸新冠病毒與接種真正安全的疫苗并不是一回事,很可能只會引發(fā)更多的混亂和痛苦。(財富中文網)
譯者:馮豐
審校: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.