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COVID-19疫苗:怕錯魔鬼了

已更新:6月 11

N. 凱瑟琳‧海爾斯加州大學洛杉磯分校英文系)


隨著輝瑞(Pfizer)與莫德納(Moderna)疫苗問世,一種新的抗病毒科技至今已觸及全球數百萬人。但許多人並不瞭解此項科技背後的含意,對其懷抱某種錯置的焦慮,卻不察這類技術之所以可怖的真正緣由。最常見的誤解大概是以為COVID-19疫苗的原理就如同先前的小兒麻痺或天花疫苗,透過將死亡或無活動力的病原接種到體內以活化免疫系統,有人於是以「不願讓任何形式的冠狀病毒進入體內」為由,拒絕施打疫苗。然而,信奉如此謬見只會適得其反:若不施打疫苗,恰恰提高感染COVID-19的機率,病毒最終還是會進到體內。


mRNA疫苗。(圖/Unsplash)

瞭解此波新疫苗究竟如何作用,有助於看清前述抗拒的謬誤之處。撇除細部差異,這兩種疫苗均使用mRNA(messenger RNA;信使核糖核酸)去穿透肌肉細胞的細胞核,使細胞膜外側生成類似冠狀病毒表面的棘蛋白(spike protein),隨後RNA便被細胞分解並吸收。生成的棘蛋白並不具有病毒的感染力,但能輕易被人體辨識為「異物」,進而「教導」(instruct)免疫系統對病毒的識別能力。疫苗第二劑與第一劑成分相同,但由於此時體內已經形成病毒抗體,免疫系統會對棘蛋白做出更劇烈的反應,所以許多人在施打第二劑後會更顯著地表現出發燒、發冷等症狀。


這項運用mRNA與細胞自身運作程序以製造出有效疫苗的技術,仰賴的是對於稱為CRISPR-Cas9的基因編輯工程十多年的研究成果。透過操作各式RNA程序與Cas9 酵素,CRISPR能對病毒(或任何)DNA進行定位精準的剪裁。此一技術為基因編輯工程帶來革命性的突破,因其精準、可用於編輯任何生物的DNA序列,價格又相對低廉。當前實驗室獲取編輯基因所需的正確RNA序列,成本不到100美元,遠低於鋅指核酸酶(Zinc-finger nucleases, ZFNs)等早先編輯技術每個基因25,000美元的花費。此外,CRISPR還能進一步對基因進行刪除、增添、插入、重排、剔除(knock-out;使基因無法產出功能性蛋白〔functional protein〕)與敲入(knock-in)等編修。前述種種編輯技術與輝瑞莫德納疫苗共通的核心特點在於,它們同樣藉助細胞本身的性能以達到人類無法自力完成的目標。人類需要與細胞的運作機制形成共生的合夥關係才能夠成功。


現在,真正的魔鬼昭然若揭:CRISPR-Cas9基因編輯技術使得人類有史以來首次可以控制演化方向,不管是對非人生命體或人類自己。如今透過修改動植物的DNA,增產、抗病、增肌、快速生長、降低睡眠需求等能力都已不是問題。同樣的改造技術也能運用於人類基因,包括精子、卵子等生殖細胞及胚胎在內,遂使改造結果被一代代複製下去。這類改變雖然可能(也已經)帶來相當效益,但同樣可能被用於邪惡的目的:比如用來製造不會感到疼痛、悔恨、同情的超人士兵,或者其他嚴重病態的人格。


簡言之,問題的癥結在於,人類的技術能力已經超越我們掌握與面對可能後果的能力,諸如全球科學家、立法者、人民、倫理學者等,針對基因編輯的程序與防護措施、衡量目標是否可接受的判準、違反規範後的制裁手段等議題,尚未有充分討論。除了與基因編輯工程直接相關的議題以外,對於人類與其他物種之間關係的深層思考也不容忽視。我們是否有權去主宰所有其他物種以追求自身利益?應該考慮非人類他者的權利嗎?誰來代其他物種發聲,又憑什麼代它們發聲?誠如前文所論,人類唯有藉助細菌RNA與Cas9酵素才能完善基因編輯技術,這正說明了(如筆者即將刊登於Critical Inquiry, summer 2021的文章所論)「共生」(symbiosis)優於「宰制」,而人類的昌盛在許多細微的方面實須歸功於其他物種,當中自然包括我們用來教導人體抵禦冠狀病毒的細菌RNA。至於病毒,縱使有害,亦可能有益於人,比如在消化或繁殖等人體活動當中扮演關鍵角色。在我們已經能像上帝一般直接介入人類與非人演化過程之際,謙卑、謹慎,以及對非人他者的尊重就成了我們必須恪守的最高價值。而傲慢、不負責、顧前不顧後等,或許才是我們該害怕的最後大魔王。



N. 凱瑟琳‧海爾斯(N. Katherine Hayles)

杜克大學文學系榮休教授,現任加州大學洛杉磯分校英文系特聘研究教授、美國文理科學院(American Academy of Arts and Sciences)成員,研究及教學專長為二十及二十一世紀文學、科學與科技之關係。著有專書十本,並逾百篇學術論文。最新著作為《候用稿:書本與流變為計算》(Postprint: Books and Becoming Computational, 2021)。


譯者:陳定甫

校對:蔡善妮

編輯:黃山耘


Fearing the Wrong Boogeyman: COVID Vaccines


N. Katherine Hayles


With the advent of the Pfizer and Moderna vaccines, a new kind of anti-viral technology has reached millions of people around the globe. Nevertheless, many do not understand the technology’s implications and feel misplaced anxieties about it, while remaining oblivious to the very real reasons why such technologies might be feared. Perhaps the most common misunderstanding is the belief that these vaccines work the same way older ones did, for example polio and smallpox, by injecting dead or inert pathogens into the body to mobilize the immune system. Some decline the vaccines reasoning that they do not want the COVID-19 virus in their bodies in any form. This belief is not only erroneous but ironically counter-productive, since declining the vaccine makes one much more susceptible to catching COVID, thus leading directly to the feared outcome.


To see why such resistances are mistaken, it helps to understand how the vaccines actually work. Although the two vaccines differ in details, both use messenger RNA (mRNA) to penetrate the nucleus of a muscle cell, where it is read as instructions to build a spike protein on the exterior of the cell wall similar to those on the surface of the COVID-19 virus. Thereafter the RNA is disassembled by the cell and absorbed. The spike protein has no functionality to create a viral cell, but it is easily recognized by the immune system as not properly belonging to the muscle cell and thus initializes the immune system to recognize the virus. The second shot is identical in composition to the first, but because the immune system has now created antibodies against the virus, it will react more vigorously to the protein spikes, which is why many people have more symptoms, such as fever and chills, to second shot than to the first.


The technique of using the cell’s own processes, via mRNA, to create the vaccine’s effectiveness draws on over a decade of research into CRISPR-Cas9 gene editing and engineering techniques, which similarly use (different versions of) RNA processes along with the enzyme Cas9 to cut viral DNA (or any DNA) at a specified location. CRISPR has revolutionized gene editing because it is precise, programmable (that is, adaptive to edit the DNA sequences of any living creature), and relatively cheap. Obtaining the correct RNA sequences tailored to the gene a researcher wants to edit costs less than a hundred dollars for scientific laboratories, compared to twenty-five thousand dollars per gene for an earlier gene editing technique such as ZFN (zinc finger nuclease). Moreover, the suite of CRISPR editing mechanisms now includes gene deletion, addition, insertion, rearrangement, knock-out (disabling the gene’s ability to create functional protein), and knock-in. The central feature that all these editing processes share among themselves and with the Pfizer and Moderna COVID vaccines is using the cell’s own capabilities to accomplish something that humans by themselves could not. Humans need the symbiotic partnership with the cell’s mechanisms to be successful.


The real boogeyman now appears, for CRISPR-Cas9 gene editing has, for the first time in human history, made it possible to direct evolution, both for nonhuman organisms and for ourselves. Plants and animals can now have their DNA altered to increase productivity, resist disease, become more muscular, grow faster, need less sleep, etc. Similar changes can be made to the human genome, including to germ line cells such as sperm, eggs and embryos that would carry the changes into all subsequent generations. Although these changes can bestow (and already have bestowed) remarkable benefits, they could also be used for nefarious ends, for example to create superhuman warriors incapable of feeing pain, remorse or empathy, or other deeply pathological characteristics.


In brief, the problem is that our technical expertise has outstripped our ability to understand and fully prepare for the consequences, including worldwide discussions among scientists, legislators, citizens, ethicists and others about safeguards and procedures for gene editing, standards for what counts as acceptable vs. unacceptable goals, and sanctions for violations. At issue are not only procedures directly relevant to gene editing and engineering but deeper concerns about the relation of humans to other species on the planet. Do we have the right to dominate all other species for our benefit? Should the rights of nonhuman others also be considered? Who speaks for them, and on what authority? Recognizing that humans can accomplish gene editing only with the assistance of bacterial RNA and Cas9 should indicate (as I argue in a forthcoming essay in Critical Inquiry, summer 2021) that symbiosis trumps dominance, and that human flourishing depends in many and subtle ways on other species, including the bacterial RNA that we use to instruct our bodies to erect defenses against COVID viruses. For their part, viruses can be benign as well as malignant and carry out processes essential for human well-being, including such bodily activities as digestion and reproduction. Humility, caution, and respect for nonhuman others must be primary values as we achieve the God-like power to intervene directly in human and nonhuman evolution. Maybe the ultimate boogeyman we should fear is human arrogance, failure to take responsibility, and obliviousness to unintended consequences.



N. Katherine Hayles, the James B. Duke Professor of Literature Emerita at Duke University and Distinguished Research Professor of English at the University of California, Los Angles, teaches and writes on the relations of literature, science, and technology in the twentieth and twenty-first centuries. She has published ten books and over one hundred peer-reviewed articles, and she is a member of the American Academy of Arts and Sciences. Her most recent book is Postprint: Books and Becoming Computational (2021).

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