Will the world need an Omicron vaccine? With the new variant of covid-19 starting to circulate around the world, many are wondering whether a new vaccine might be needed. The major covid-19 vaccine makers, such as Pfizer-BioNTech, Moderna and J&J have already said they are initiating development of an Omicron-specific vaccine against covid-19. Whether or not these will be needed, though, remains to be seen. Pfizer/BioNtech and Moderna, makers of mRNA vaccines, developed other variant-specific vaccines (against Beta and Delta). But ultimately existing vaccines proved sufficient. Although the vaccines were unable to halt the transmission of the Delta strain, they have held up well at preventing serious cases of covid. But unused vaccines were not wasted efforts. By putting variant vaccines through small clinical trials, firms have gathered evidence that will be useful when trying to convince regulators that an Omicron-specific vaccine is safe as well, if it is needed. Will the world need an Omicron vaccine? 世界需要奧米克戎疫苗嗎? With the new variant of covid-19 starting to circulate around the world, many are wondering whether a new vaccine might be needed. The major covid-19 vaccine makers, such as Pfizer-BioNTech, Moderna and J&J have already said they are initiating development of an Omicron-specific vaccine against covid-19. Whether or not these will be needed, though, remains to be seen. 隨著新冠病毒的新型變異毒株開始肆虐全球,許多人想知道是否需要接種新疫苗。新冠疫苗的主要生產(chǎn)商(比如輝瑞-百歐恩泰,莫德納和強(qiáng)生)已表示,他們正在著手研發(fā)一種針對奧米克戎毒株的疫苗。不過,疫苗是否需要補(bǔ)種,還有待觀察。
王不留(wbliu85)注: 輝瑞和BioNTech是兩家公司。Pfizer中文名是輝瑞,Biotech中文名是百歐恩泰。這兩家公司聯(lián)合研發(fā)了一款新冠疫苗— Pfizer-BioNTech疫苗 或?qū)懽?Pfizer/BioNTech疫苗。 Pfizer/BioNtech and Moderna, makers of mRNA vaccines, developed other variant-specific vaccines (against Beta and Delta). But ultimately existing vaccines proved sufficient. Although the vaccines were unable to halt the transmission of the Delta strain, they have held up well at preventing serious cases of covid. 輝瑞-百歐恩泰和莫德納這樣的mRNA疫苗生產(chǎn)商,已研發(fā)出其它變異毒株的疫苗(比如貝塔和德爾塔)。最終證明現(xiàn)有疫苗已經(jīng)足夠。盡管疫苗無法阻止德爾塔毒株的傳播,但它們在降低新冠重癥病例數(shù)方面表現(xiàn)良好。
But unused vaccines were not wasted efforts. By putting variant vaccines through small clinical trials, firms have gathered evidence that will be useful when trying to convince regulators that an Omicron-specific vaccine is safe as well, if it is needed. 然而,未投入使用的疫苗并不是白費(fèi)力氣。(這句話的意思:雖然現(xiàn)有疫苗能夠預(yù)防奧米克戎,但各公司研發(fā)針對奧米克戎的疫苗,也不是白費(fèi)力氣。)通過對變異病毒疫苗進(jìn)行小型臨床試驗(yàn),各公司收集到的證據(jù)有助于說服監(jiān)管機(jī)構(gòu),如有需要,奧米克戎疫苗也是安全的。
王不留(wbliu85)注: 從2019年開始,新冠病毒已歷經(jīng)數(shù)次變異。比如英國alpha和印度的delta。 下圖是新冠病毒變異株的大家族,世界衛(wèi)生組織給目前造成嚴(yán)重疫情的變種的命名和他們出現(xiàn)的時(shí)間。 下圖是《科學(xué)》雜志最新發(fā)表的新冠變異株的進(jìn)化樹,根據(jù)新冠棘突蛋白的S1亞單位變異情況繪制,可見從疫情初始到現(xiàn)在層出不窮的各種變異株。 最新出現(xiàn)的變異毒株奧米克戎來自南非,主要發(fā)現(xiàn)在一些HIV感染病人中,以下是它的三維標(biāo)準(zhǔn)全身照(下圖左側(cè),藍(lán)色突起為棘突蛋白)和棘突蛋白的三維標(biāo)準(zhǔn)照(下圖右側(cè))。 在右圖里和它的兩位前輩(下圖右邊第一個(gè),原始毒株,右邊第二個(gè),delta )相比,確實(shí)有不少變化,多了很多正電荷(藍(lán)色點(diǎn))和中性電荷(白色點(diǎn))。藍(lán)色點(diǎn)代表正電荷, 紅色點(diǎn)代表負(fù)電荷, 而白色點(diǎn)則是中性電荷。 科學(xué)家們目前對它的擔(dān)憂來自三方面:
醫(yī)學(xué)專家們更擔(dān)心的是全球疫苗接種的不平衡,這次出的新變異就是在南非這樣接種率低的國家首發(fā)的。很明顯接種率在經(jīng)濟(jì)相對落后的地方要低很多。 如上圖的左圖所示, 富有的國家在過去四個(gè)月內(nèi)接種的加強(qiáng)針比窮國全年給的基本接種都多出很多。右圖,柱狀體紅色部分顯示未接種比例,可以看出最后一柱低收入人群的未接種比例極高,明顯在85-95% 之間,而隨著收入增高,未接種比例逐漸減少,高收入人群中接種比例超過75%。 真心希望疫情早日過去,迎來嶄新美好的2022年。 |
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