如今,新冠疫情導(dǎo)致諸多行業(yè)遭遇嚴(yán)重混亂。但在醫(yī)藥行業(yè)里,有個亮點卻熠熠生輝:新冠疫苗的研發(fā)。目前在研的新冠病毒疫苗包括滅活疫苗、腺病毒載體疫苗和mRNA疫苗,另外還有重組亞單位、合成多肽、DNA等新冠疫苗均在研制中。
“我認為人類正身處疫苗開發(fā)的新黃金時代。”比爾及梅琳達·蓋茨醫(yī)學(xué)研究所的首席執(zhí)行官彭妮·希頓說。
各類新冠疫苗中,mRNA疫苗備受關(guān)注。
mRNA疫苗屬于核酸疫苗。核酸疫苗主要分為DNA型疫苗和RNA型疫苗。DNA型疫苗多應(yīng)用于腫瘤,而目前在研的新型新冠疫苗多屬mRNA型疫苗。
mRNA疫苗的原理是是將RNA在體外進行相關(guān)的修飾后傳遞至機體細胞內(nèi)表達并產(chǎn)生蛋白抗原,從而導(dǎo)機體產(chǎn)生針對該抗原的免疫應(yīng)答,進而擴大機體的免疫能力。
專家表示,像輝瑞/BioNTech和Moderna為疫情制造mRNA疫苗一樣,利用身體代碼治療疾病的潛力,應(yīng)用范疇將遠遠超出當(dāng)前的疫情。
有些人甚至聲稱RNA和DNA療法將改變?nèi)祟惻c疾病之間的關(guān)系。這意味著將出現(xiàn)新一波技術(shù)投入和探索浪潮,對疫苗市場的整體興趣也會激增。
“人們已經(jīng)開始認真考慮疫苗業(yè)務(wù)的經(jīng)濟性,以及如何獲得先發(fā)優(yōu)勢才能夠確保疫苗制造商獲得長期的市場主導(dǎo)地位。”SVB Leerink的分析師杰弗里·波格斯說。
前景
為了尋找有效的新冠疫苗,全球各地的開發(fā)者嘗試了各種疫苗技術(shù)。結(jié)果是全球各國批準(zhǔn)的疫苗各式各樣,實現(xiàn)免疫程度也各不相同。
包括現(xiàn)在家喻戶曉的輝瑞/BioNTech和Moderna在內(nèi),有幾家公司轉(zhuǎn)向了從未公開使用但研究已經(jīng)超過25年,也有一些臨床試驗支持的技術(shù):合成信使RNA技術(shù)。兩款mRNA疫苗的免疫效果相當(dāng)突出,也大大提升了其制造商(對輝瑞的提升更明顯)的地位。
當(dāng)前情況也明確表明,mRNA疫苗可以成為有效的防疫工具。
“通過核酸疫苗,人們發(fā)現(xiàn)疫苗能夠迅速量產(chǎn)。”通用電氣的DNA疫苗相關(guān)項目首席研究員約翰·納爾遜表示,該項目由美國國防部高級研究計劃局資助。
跟其他疫苗不一樣,RNA和DNA疫苗生產(chǎn)過程涉及裝配核酸,以及將脆弱的遺傳物質(zhì)封裝以順利進入細胞。目前的疫苗產(chǎn)品中,封裝后會變成極小的脂肪粒。但納爾遜說,也可以使用其他技術(shù)。
這一過程意味著,與其他必須培養(yǎng)有效成分的疫苗相比,mRNA疫苗的制造速度快,調(diào)整也相對容易。舉例來說,剛開始,mRNA技術(shù)主要用于制造個性化癌癥藥,不過并未大規(guī)模應(yīng)用。
但mRNA在個性化醫(yī)學(xué)領(lǐng)域中確實很有潛力。從季節(jié)性流感疫苗之類變化迅速的應(yīng)用,到迄今無法治療的病毒,例如寨卡病毒和酶缺乏等之前“無藥可醫(yī)”的疾病,前景非常大。
從長遠來看,“多數(shù)乃至所有病毒性疾病疫苗都有望應(yīng)用。”波格斯說。
然而對mRNA疫苗制造商來說,某些特性可能并不值得挑戰(zhàn)。
“比如挑戰(zhàn)默沙東的宮頸癌疫苗加德西,或葛蘭素史克的帶狀皰疹疫苗欣安立適,挑戰(zhàn)非常大,因為標(biāo)準(zhǔn)非常高。”波格斯說。
他預(yù)計,mRNA疫苗開發(fā)者將開始對經(jīng)濟前景上佳的病癥進行臨床前研究,但對于已經(jīng)存在有效疫苗的疾病,即便為高效疫苗投入昂貴冗長的臨床試驗時,成本效益計算也會有所不同。在某些情況下,加德西的有效性接近100%,而欣安立適的防護幾率也比較接近。
傳統(tǒng)上,所有疫苗的免疫力都能夠超過50%,但對于當(dāng)前已經(jīng)有高效防護選擇的市場,標(biāo)準(zhǔn)只會更高。
mRNA實驗從當(dāng)前無法治療的疾病開始可能性比較大,至于已經(jīng)存在高效疫苗的某些疾病可能永遠不會開發(fā)。
投資潮
2020年年初,mRNA疫苗已經(jīng)出現(xiàn)突破,但之前從未量產(chǎn)。
Shore Capital的制藥行業(yè)分析師亞當(dāng)·巴克稱:“在新冠疫情之前,概念無法證明。”
“大部分RNA疫苗仍然處于臨床前動物研究階段。”希頓說。少數(shù)已經(jīng)進入人體試驗階段的傳染病mRNA疫苗都處于早期階段,其中包括流感和狂犬病疫苗。癌癥治療和疫苗也在試驗中。
mRNA應(yīng)用技術(shù)也剛剛出現(xiàn)。將mRNA穩(wěn)妥送入細胞的方法在2010年代后期才剛由科學(xué)家改進,運送mRNA的微小脂肪粒技術(shù)上稱為脂質(zhì)納米顆粒。
“當(dāng)時我估計要出現(xiàn)獲批的RNA疫苗大概還需要5到7年的時間。”希頓說。
不過在新冠疫情中,前所未有的合作環(huán)境和政府投資徹底改變了一切,幾個月內(nèi)就通過有效性數(shù)據(jù)和大規(guī)模應(yīng)用為疫苗提供了概念性驗證。
“政府支持幫助制造商在風(fēng)險中擴大規(guī)模,同時獲取了第一批有效性數(shù)據(jù)。”希頓說。
如此一來,當(dāng)三階段研究完成,藥物準(zhǔn)備提交監(jiān)管部門批準(zhǔn)時,企業(yè)就已經(jīng)開始儲備劑量。
而政府的大力支持也讓Moderna從小型生物技術(shù)公司迅速成長為知名制造商,在通用電氣向美國國防部高級研究計劃局爭取的DNA合同中負責(zé)RNA部分。
休斯頓衛(wèi)理公會的RNA治療學(xué)項目醫(yī)學(xué)主任約翰·庫克說,學(xué)界對其他領(lǐng)域應(yīng)用RNA研究的興趣和商業(yè)投資也大為增加。
他表示:“該領(lǐng)域發(fā)展勢頭似乎很猛,吸引了不少人員和資金。”
局限性
雖然RNA疫苗和其他療法似乎前景光明,但也有諸多局限性。“我現(xiàn)在最擔(dān)心溫度穩(wěn)定性、儲存條件和價格。”希頓說,“不過,問題都可以解決。”
技術(shù)能夠在溫度更高的條件下讓疫苗保持的穩(wěn)定。疫苗可以(而且很多人表示應(yīng)該)獲得補貼。
這樣可能對全球衛(wèi)生領(lǐng)域產(chǎn)生巨大影響,進而影響全球底線。
有人提出以市場為基礎(chǔ)的戰(zhàn)略,例如向疫苗公司加大補貼從而為貧困國家生產(chǎn)疫苗,能夠迅速解決問題,不管在財政還是倫理方面都至關(guān)重要。
“新冠疫情的一大重要教訓(xùn)是,制藥行業(yè)提供的巨大益處必須考慮到世界上最貧窮的人們。”最近,兩位公共衛(wèi)生專家在一篇社論中指出。
但即便技術(shù)變革和疫苗公平出現(xiàn)進步,希頓還是提醒稱,并非所有病毒都像新冠病毒一樣容易鎖定目標(biāo)。新冠病毒有標(biāo)志性的刺突蛋白,進入細胞開始復(fù)制的機制相當(dāng)簡單。針對其他病毒時,找出正確靶位以及使用哪種病毒RNA才是巨大挑戰(zhàn)。
“突破需要創(chuàng)新。”希頓說。
新冠病毒基因序列發(fā)布42天后,Moderna就可以生產(chǎn)出第一款疫苗。
基因序列由上海公共衛(wèi)生臨床中心和公共衛(wèi)生學(xué)院的張永珍領(lǐng)導(dǎo)的科學(xué)家團隊發(fā)布,這一消息本身就代表著科學(xué)家之間采取了不同尋常的合作。
去年,學(xué)術(shù)界、工業(yè)界和政府之間在疫苗方面也實現(xiàn)了史無前例的合作。
希頓表示,找到合適的方式繼續(xù)合作并在此基礎(chǔ)上再接再厲,對保持疫苗學(xué)黃金時代的發(fā)展勢頭至關(guān)重要。
“經(jīng)驗只有實際應(yīng)用時才能夠真正學(xué)到。”她說,“除非改變做法。”
mRNA疫苗下一步如何發(fā)展?
新冠疫情仍然在持續(xù),它影響了生活的各方各面,現(xiàn)在要估計確切的時間表還比較困難。
巴克預(yù)計可以嘗試癌癥治療早期探索,特別是現(xiàn)在關(guān)于mRNA和癌癥的數(shù)據(jù)非常豐富。疫情開始時,個性化癌癥疫苗就已經(jīng)在試驗中,而且與其他治療方法相比有效性相當(dāng)高。
但巴克也提醒稱,傳染病領(lǐng)域能否廣泛應(yīng)用RNA疫苗“最終取決于新冠疫苗的長期數(shù)據(jù)”。
目前已經(jīng)應(yīng)用的兩款mRNA疫苗都尚未獲得美國食品與藥品管理局的全面批準(zhǔn)。人們都知道該疫苗對人體不會造成傷害,也可以激發(fā)較高的免疫力,但不清楚免疫力能夠維持多久。
波格斯說,制藥公司雖然面臨不確定性,但并未停止臨床前研究。至于傳染病方面,他預(yù)計季節(jié)性流感、巨細胞病毒和目前沒有疫苗的熱帶傳染病將最先出現(xiàn)成果。
不過“并非每款mRNA疫苗都可以像新冠疫苗一樣發(fā)生強烈反應(yīng)。”巴克也警告稱。
庫克說,直接利用RNA治療已經(jīng)開始人體試驗,其中包括將未封裝的RNA直接注射到相關(guān)器官。2019年,Moderna對開腔心臟手術(shù)患者心臟再生的治療進行了一階段試驗。
“使用14號針加上強壯的手臂,就能夠到達身體任何部位。”庫克說。他指出,現(xiàn)在如果將脂質(zhì)納米顆粒注射到血液中,除了身體過濾器肝臟和脾臟,對其他器官都起不了什么作用。
對新冠疫苗來說這點并不重要,因為疫苗注射到手臂肌肉中就可以激發(fā)免疫力(這就是為什么注射之后有些人手臂會酸痛)。靶向治療需要直接到位。情況可能出現(xiàn)變化,他的團隊以及其他人都在研究新的更復(fù)雜的方法,能夠?qū)⑺幬镒⑸涞窖褐校瑥亩贿\送到身體相關(guān)部位,不再需要14號針頭。
匈牙利科學(xué)家卡塔林·卡里科曾經(jīng)冒著職業(yè)風(fēng)險研發(fā)mRNA療法,她發(fā)現(xiàn)輝瑞疫苗如此高效時簡直欣喜若狂。
四十年基本上從未獲承認的工作中,“我一直想象著可以治療的各種疾病。”她對《每日電訊報》表示。
現(xiàn)在和不久的將來,在BioNTech工作的卡里科將見證全行業(yè)認可她的想法并付諸實施。(財富中文網(wǎng))
譯者:梁宇
審校:夏林
如今,新冠疫情導(dǎo)致諸多行業(yè)遭遇嚴(yán)重混亂。但在醫(yī)藥行業(yè)里,有個亮點卻熠熠生輝:新冠疫苗的研發(fā)。目前在研的新冠病毒疫苗包括滅活疫苗、腺病毒載體疫苗和mRNA疫苗,另外還有重組亞單位、合成多肽、DNA等新冠疫苗均在研制中。
“我認為人類正身處疫苗開發(fā)的新黃金時代。”比爾及梅琳達·蓋茨醫(yī)學(xué)研究所的首席執(zhí)行官彭妮·希頓說。
各類新冠疫苗中,mRNA疫苗備受關(guān)注。
mRNA疫苗屬于核酸疫苗。核酸疫苗主要分為DNA型疫苗和RNA型疫苗。DNA型疫苗多應(yīng)用于腫瘤,而目前在研的新型新冠疫苗多屬mRNA型疫苗。
mRNA疫苗的原理是是將RNA在體外進行相關(guān)的修飾后傳遞至機體細胞內(nèi)表達并產(chǎn)生蛋白抗原,從而導(dǎo)機體產(chǎn)生針對該抗原的免疫應(yīng)答,進而擴大機體的免疫能力。
專家表示,像輝瑞/BioNTech和Moderna為疫情制造mRNA疫苗一樣,利用身體代碼治療疾病的潛力,應(yīng)用范疇將遠遠超出當(dāng)前的疫情。
有些人甚至聲稱RNA和DNA療法將改變?nèi)祟惻c疾病之間的關(guān)系。這意味著將出現(xiàn)新一波技術(shù)投入和探索浪潮,對疫苗市場的整體興趣也會激增。
“人們已經(jīng)開始認真考慮疫苗業(yè)務(wù)的經(jīng)濟性,以及如何獲得先發(fā)優(yōu)勢才能夠確保疫苗制造商獲得長期的市場主導(dǎo)地位。”SVB Leerink的分析師杰弗里·波格斯說。
前景
為了尋找有效的新冠疫苗,全球各地的開發(fā)者嘗試了各種疫苗技術(shù)。結(jié)果是全球各國批準(zhǔn)的疫苗各式各樣,實現(xiàn)免疫程度也各不相同。
包括現(xiàn)在家喻戶曉的輝瑞/BioNTech和Moderna在內(nèi),有幾家公司轉(zhuǎn)向了從未公開使用但研究已經(jīng)超過25年,也有一些臨床試驗支持的技術(shù):合成信使RNA技術(shù)。兩款mRNA疫苗的免疫效果相當(dāng)突出,也大大提升了其制造商(對輝瑞的提升更明顯)的地位。
當(dāng)前情況也明確表明,mRNA疫苗可以成為有效的防疫工具。
“通過核酸疫苗,人們發(fā)現(xiàn)疫苗能夠迅速量產(chǎn)。”通用電氣的DNA疫苗相關(guān)項目首席研究員約翰·納爾遜表示,該項目由美國國防部高級研究計劃局資助。
跟其他疫苗不一樣,RNA和DNA疫苗生產(chǎn)過程涉及裝配核酸,以及將脆弱的遺傳物質(zhì)封裝以順利進入細胞。目前的疫苗產(chǎn)品中,封裝后會變成極小的脂肪粒。但納爾遜說,也可以使用其他技術(shù)。
這一過程意味著,與其他必須培養(yǎng)有效成分的疫苗相比,mRNA疫苗的制造速度快,調(diào)整也相對容易。舉例來說,剛開始,mRNA技術(shù)主要用于制造個性化癌癥藥,不過并未大規(guī)模應(yīng)用。
但mRNA在個性化醫(yī)學(xué)領(lǐng)域中確實很有潛力。從季節(jié)性流感疫苗之類變化迅速的應(yīng)用,到迄今無法治療的病毒,例如寨卡病毒和酶缺乏等之前“無藥可醫(yī)”的疾病,前景非常大。
從長遠來看,“多數(shù)乃至所有病毒性疾病疫苗都有望應(yīng)用。”波格斯說。
然而對mRNA疫苗制造商來說,某些特性可能并不值得挑戰(zhàn)。
“比如挑戰(zhàn)默沙東的宮頸癌疫苗加德西,或葛蘭素史克的帶狀皰疹疫苗欣安立適,挑戰(zhàn)非常大,因為標(biāo)準(zhǔn)非常高。”波格斯說。
他預(yù)計,mRNA疫苗開發(fā)者將開始對經(jīng)濟前景上佳的病癥進行臨床前研究,但對于已經(jīng)存在有效疫苗的疾病,即便為高效疫苗投入昂貴冗長的臨床試驗時,成本效益計算也會有所不同。在某些情況下,加德西的有效性接近100%,而欣安立適的防護幾率也比較接近。
傳統(tǒng)上,所有疫苗的免疫力都能夠超過50%,但對于當(dāng)前已經(jīng)有高效防護選擇的市場,標(biāo)準(zhǔn)只會更高。
mRNA實驗從當(dāng)前無法治療的疾病開始可能性比較大,至于已經(jīng)存在高效疫苗的某些疾病可能永遠不會開發(fā)。
投資潮
2020年年初,mRNA疫苗已經(jīng)出現(xiàn)突破,但之前從未量產(chǎn)。
Shore Capital的制藥行業(yè)分析師亞當(dāng)·巴克稱:“在新冠疫情之前,概念無法證明。”
“大部分RNA疫苗仍然處于臨床前動物研究階段。”希頓說。少數(shù)已經(jīng)進入人體試驗階段的傳染病mRNA疫苗都處于早期階段,其中包括流感和狂犬病疫苗。癌癥治療和疫苗也在試驗中。
mRNA應(yīng)用技術(shù)也剛剛出現(xiàn)。將mRNA穩(wěn)妥送入細胞的方法在2010年代后期才剛由科學(xué)家改進,運送mRNA的微小脂肪粒技術(shù)上稱為脂質(zhì)納米顆粒。
“當(dāng)時我估計要出現(xiàn)獲批的RNA疫苗大概還需要5到7年的時間。”希頓說。
不過在新冠疫情中,前所未有的合作環(huán)境和政府投資徹底改變了一切,幾個月內(nèi)就通過有效性數(shù)據(jù)和大規(guī)模應(yīng)用為疫苗提供了概念性驗證。
“政府支持幫助制造商在風(fēng)險中擴大規(guī)模,同時獲取了第一批有效性數(shù)據(jù)。”希頓說。
如此一來,當(dāng)三階段研究完成,藥物準(zhǔn)備提交監(jiān)管部門批準(zhǔn)時,企業(yè)就已經(jīng)開始儲備劑量。
而政府的大力支持也讓Moderna從小型生物技術(shù)公司迅速成長為知名制造商,在通用電氣向美國國防部高級研究計劃局爭取的DNA合同中負責(zé)RNA部分。
休斯頓衛(wèi)理公會的RNA治療學(xué)項目醫(yī)學(xué)主任約翰·庫克說,學(xué)界對其他領(lǐng)域應(yīng)用RNA研究的興趣和商業(yè)投資也大為增加。
他表示:“該領(lǐng)域發(fā)展勢頭似乎很猛,吸引了不少人員和資金。”
局限性
雖然RNA疫苗和其他療法似乎前景光明,但也有諸多局限性。“我現(xiàn)在最擔(dān)心溫度穩(wěn)定性、儲存條件和價格。”希頓說,“不過,問題都可以解決。”
技術(shù)能夠在溫度更高的條件下讓疫苗保持的穩(wěn)定。疫苗可以(而且很多人表示應(yīng)該)獲得補貼。
這樣可能對全球衛(wèi)生領(lǐng)域產(chǎn)生巨大影響,進而影響全球底線。
有人提出以市場為基礎(chǔ)的戰(zhàn)略,例如向疫苗公司加大補貼從而為貧困國家生產(chǎn)疫苗,能夠迅速解決問題,不管在財政還是倫理方面都至關(guān)重要。
“新冠疫情的一大重要教訓(xùn)是,制藥行業(yè)提供的巨大益處必須考慮到世界上最貧窮的人們。”最近,兩位公共衛(wèi)生專家在一篇社論中指出。
但即便技術(shù)變革和疫苗公平出現(xiàn)進步,希頓還是提醒稱,并非所有病毒都像新冠病毒一樣容易鎖定目標(biāo)。新冠病毒有標(biāo)志性的刺突蛋白,進入細胞開始復(fù)制的機制相當(dāng)簡單。針對其他病毒時,找出正確靶位以及使用哪種病毒RNA才是巨大挑戰(zhàn)。
“突破需要創(chuàng)新。”希頓說。
新冠病毒基因序列發(fā)布42天后,Moderna就可以生產(chǎn)出第一款疫苗。
基因序列由上海公共衛(wèi)生臨床中心和公共衛(wèi)生學(xué)院的張永珍領(lǐng)導(dǎo)的科學(xué)家團隊發(fā)布,這一消息本身就代表著科學(xué)家之間采取了不同尋常的合作。
去年,學(xué)術(shù)界、工業(yè)界和政府之間在疫苗方面也實現(xiàn)了史無前例的合作。
希頓表示,找到合適的方式繼續(xù)合作并在此基礎(chǔ)上再接再厲,對保持疫苗學(xué)黃金時代的發(fā)展勢頭至關(guān)重要。
“經(jīng)驗只有實際應(yīng)用時才能夠真正學(xué)到。”她說,“除非改變做法。”
mRNA疫苗下一步如何發(fā)展?
新冠疫情仍然在持續(xù),它影響了生活的各方各面,現(xiàn)在要估計確切的時間表還比較困難。
巴克預(yù)計可以嘗試癌癥治療早期探索,特別是現(xiàn)在關(guān)于mRNA和癌癥的數(shù)據(jù)非常豐富。疫情開始時,個性化癌癥疫苗就已經(jīng)在試驗中,而且與其他治療方法相比有效性相當(dāng)高。
但巴克也提醒稱,傳染病領(lǐng)域能否廣泛應(yīng)用RNA疫苗“最終取決于新冠疫苗的長期數(shù)據(jù)”。
目前已經(jīng)應(yīng)用的兩款mRNA疫苗都尚未獲得美國食品與藥品管理局的全面批準(zhǔn)。人們都知道該疫苗對人體不會造成傷害,也可以激發(fā)較高的免疫力,但不清楚免疫力能夠維持多久。
波格斯說,制藥公司雖然面臨不確定性,但并未停止臨床前研究。至于傳染病方面,他預(yù)計季節(jié)性流感、巨細胞病毒和目前沒有疫苗的熱帶傳染病將最先出現(xiàn)成果。
不過“并非每款mRNA疫苗都可以像新冠疫苗一樣發(fā)生強烈反應(yīng)。”巴克也警告稱。
庫克說,直接利用RNA治療已經(jīng)開始人體試驗,其中包括將未封裝的RNA直接注射到相關(guān)器官。2019年,Moderna對開腔心臟手術(shù)患者心臟再生的治療進行了一階段試驗。
“使用14號針加上強壯的手臂,就能夠到達身體任何部位。”庫克說。他指出,現(xiàn)在如果將脂質(zhì)納米顆粒注射到血液中,除了身體過濾器肝臟和脾臟,對其他器官都起不了什么作用。
對新冠疫苗來說這點并不重要,因為疫苗注射到手臂肌肉中就可以激發(fā)免疫力(這就是為什么注射之后有些人手臂會酸痛)。靶向治療需要直接到位。情況可能出現(xiàn)變化,他的團隊以及其他人都在研究新的更復(fù)雜的方法,能夠?qū)⑺幬镒⑸涞窖褐校瑥亩贿\送到身體相關(guān)部位,不再需要14號針頭。
匈牙利科學(xué)家卡塔林·卡里科曾經(jīng)冒著職業(yè)風(fēng)險研發(fā)mRNA療法,她發(fā)現(xiàn)輝瑞疫苗如此高效時簡直欣喜若狂。
四十年基本上從未獲承認的工作中,“我一直想象著可以治療的各種疾病。”她對《每日電訊報》表示。
現(xiàn)在和不久的將來,在BioNTech工作的卡里科將見證全行業(yè)認可她的想法并付諸實施。(財富中文網(wǎng))
譯者:梁宇
審校:夏林
The COVID-19 pandemic has caused profound disruption in many industries, most of it negative. But in the pharmaceutical industry, a bright spot shines.
“I think we are in this new golden age of vaccinology,” says Penny Heaton, chief executive officer of the Bill & Melinda Gates Medical Research Institute.
Experts say the potential of using our body’s code to teach it how to treat illness, as mRNA vaccines from Pfizer/BioNTech and Moderna do for COVID-19, goes far beyond the current pandemic. Some even go so far as to say that RNA and DNA treatments will transform our relationship with disease. What this adds up to is a wave of investment and exploration in the newly proven technology—and a surge of interest in the vaccine market overall.
“People have started to really think about the economics of the vaccine business, and how an early-mover advantage can lead to a dominant long-term market position for a vaccine manufacturer,” says analyst Geoffrey Porges of SVB Leerink.
The prospects
In the search for effective COVID-19 vaccines, developers around the world tried a wide spread of vaccine technologies. The result is a diversity of vaccines approved globally that provoke varying levels of immunity.
A few, including now-household names Pfizer/BioNTech and Moderna, turned to a technology that had never been used in public but had more than 25 years of research and some clinical trials to back it up: synthetically produced messenger RNA. The standout immunity produced by the two successful mRNA vaccines rocketed their makers to (in Pfizer’s case, even greater) prominence.
It also provided stark proof of concept that mRNA vaccines could be a powerful tool against disease. “The promise that a nucleic acid vaccine gives is that it can be made so rapidly,” says John Nelson, General Electric’s lead researcher on a related project for DNA vaccines funded through the Defense Advanced Research Projects Agency (DARPA).
Unlike other vaccine types, producing RNA and DNA vaccines is a matter of assembling nucleic acids and packaging the fragile genetic material in such a way as to protect it until it can make it into a cell. In the case of current vaccines, that package is a tiny particle of fat. But other technologies can be used, says Nelson.
This process means the vaccines are quick to make, compared to other kinds of vaccines that use components that have to be grown, and they can be modified with relative ease. mRNA technology, for instance, was first developed for use in personalized cancer medicine, although it has yet to be implemented at a large scale.
But mRNA has potential beyond personalized medicine. From quick-turnaround applications like seasonal influenza vaccines to as-yet-untreated viruses such as Zika and previously “undruggable” diseases like enzyme deficiencies, its possibilities abound. In the long term, “most or all of the viral disease vaccines are up for grabs,” Porges says.
For mRNA vaccine makers, however, some properties may never be worth challenging. “Breaking in against, for example, Merck’s Gardasil or Glaxo’s Shingrix, that’s got to be more challenging, because the bar is already pretty high,” says Porges.
He expects mRNA vaccine developers to embark on preclinical research on those big-ticket properties, but the cost-benefit calculation for taking even a very effective vaccine into expensive and lengthy clinical trials will be different for conditions that already have effective vaccines. Gardasil has nearly 100% effectiveness in some cases, while Shingrix’s effectiveness is almost that high.
Any vaccine that confers more than 50% immunity is traditionally considered to be effective, but for existing markets with already highly effective options, the bar is much higher. mRNA experimentation is more likely to start with conditions without existing treatments and may never be conducted for some conditions for which highly effective vaccines already exist.
Wave of investment
At the beginning of 2020, mRNA vaccines had promise. But they had never been scaled before.
“Before COVID, there was no proof of concept,” says Adam Barker, a pharmaceutical analyst at Shore Capital.
“Most of the RNA vaccines were still in preclinical animal studies,” says Heaton. The few mRNA vaccines for infectious disease that had reached human trials, including for influenza and rabies, were in early stages. Cancer treatments and vaccines were also in trials.
And the technologies that made mRNA useful were just emerging. A reliable method for getting mRNA into cells—those tiny particles of fat, technically called lipid nanoparticles—had just been optimized by scientists in the late 2010s.
“I would estimate we were probably five to seven years away from having a licensed RNA vaccine in late 2019,” Heaton says.
The unprecedented collaborative environment and government investment prompted by the COVID-19 pandemic entirely changed that reality and provided both proof of concept for the vaccines, in the form of efficacy data and massive scale, in a matter of months.
“The fact that there was government support allowed manufacturers to scale up at risk, and to do that simultaneously while getting that first efficacy data,” Heaton says. That way, when Phase III studies were completed, and the drug was ready to be submitted for regulatory approval, companies were already stockpiling doses.
That kind of support allowed Moderna to rise from a small biotech to a prominent manufacturer who received the RNA portion of the DARPA contract that GE received for DNA. Elsewhere, says John Cooke, medical director of Houston Methodist’s RNA Therapeutics Program, academic interest and business investment in RNA research have spiked.
“There just seems to be a lot more momentum in the field,” he says. “It has attracted personnel and funding.”
Limitations
RNA vaccines and other therapies appear to have a bright future. But there are a number of limitations to their potential. “My biggest qualm right now is the temperature stability, the storage conditions, and the price,” says Heaton. “That said, these are problems that can be solved.”
Technology to keep the vaccines stable at higher temperatures can be developed. Vaccines can (and, many say, should) be subsidized.
Doing so could make a massive difference for global health and thus the global bottom line. Market-based strategies such as deeply subsidizing vaccine companies to produce vaccines for poorer countries have been proposed to quickly move on this issue, which will be an essential one, both financially and morally. “A key lesson of COVID-19 is that the great benefits the pharmaceutical sector has to offer must fully include the world’s poorest people,” two public health experts stated in a recent editorial proposing just this approach.
But even if technological change and advances in vaccine equity happen, Heaton also cautions that not all viruses will be as easy to target as COVID-19. The now-iconic spike protein represents a fairly simple mechanism for the SARS-CoV-2 virus to get into cells and begin replicating. Figuring out the correct parts of the virus to target and which specific viral RNA to use will be a much bigger challenge for many other viruses.
“It’s going to take innovation,” Heaton says.
Moderna was able to produce its first version of its vaccine just 42 days after the release of the SARS-CoV-2 genome’s sequence. That release, by a consortium of scientists headed by Yong-Zhen Zhang of the Shanghai Public Health Clinical Center & School of Public Health, was itself unusual evidence of collaboration between scientists.
Collaboration between academics, industry, and government has been the watchword of the last unprecedented year in vaccinology. Heaton says finding a way to continue that collaboration and build on it will be essential to maintaining the momentum of vaccinology’s golden age.
“A lesson isn’t learned until it’s actually applied,” she says, “until we decide what we are going to do differently.”
What’s next for mRNA vaccines? Since the COVID-19 pandemic is still very much ongoing, interrupting all facets of life, it’s hard to estimate the exact timeline. Barker anticipates that cancer treatments will be an early area of exploration, especially since there’s already so much data about mRNA and cancer. Personalized cancer vaccines were already in trial when the COVID-19 pandemic began, showing a high degree of effectiveness compared to other treatments.
But the widespread use of RNA vaccines for infectious diseases “ultimately depends on what the long-term data on the COVID vaccine is,” Barker cautions. Neither mRNA vaccine currently in use has received full FDA approval yet. Although we know they don’t hurt people and they do produce a high level of immunity, we don’t yet know how long-lasting that immunity is.
This uncertainty hasn’t stopped many drug companies from embarking on at least preclinical research, says Porges. When it comes to infectious diseases, he expects that seasonal influenza, cytomegalovirus, and tropical infectious diseases that don’t currently have a vaccine will be some of the first areas where we see results. But “it won’t be the case that every vaccine based on mRNA will have the same kind of strong response [as the COVID-19 vaccines],” cautions Barker.
Direct RNA treatments, which involve injecting unencapsulated RNA directly into the relevant organs, are already being trialed in humans, says Cooke. In 2019, Moderna’s treatment for heart regeneration in open-heart surgery patients passed through Phase I testing.
“With a 14-gauge needle and a strong arm, you can reach any area in the body,” Cooke says. Right now, lipid nanoparticles, if injected into your bloodstream, don’t do a great job of reaching any organs except the body’s filters, the liver and spleen, he says. That doesn’t matter for the COVID-19 vaccines, since they’re injected into the muscle of your arm and they start provoking immunity from there (that’s why some people get sore arms afterward). Targeted therapies need to be delivered directly. That could change: His team as well as others are working on new, more sophisticated formulations that would allow the drugs to be injected into the bloodstream and carried to the relevant part of the body—no 14-gauge needles involved.
When Katalin Karikó, the Hungarian-born scientist who risked her career to develop mRNA therapy, found out about the Pfizer vaccine’s efficacy, she was overjoyed. During the four decades of largely unacknowledged work, “I imagined all the diseases I could treat,” she told the Telegraph. Now and in the near future, Karikó, who now works for BioNTech, will watch an entire industry take her idea and run with it.