這是我們第4期文章，英文1052，中文1913，
感謝閱讀。
If you say US’s election is the most significant event that occurred in 2020, then I』d say the development of vaccines for Covid-19 would come in second. More than ninety teams of experts and pharmaceutical companies had been working days and nights to develop potential preventions for the first-ever coronavirus pandemic in history. But what are vaccines? Are they safe? What makes them so hard to be made?
如果您說美國大選是2020年最重要的事件，那麼我想說的是Covid-19疫苗的研發絕不亞於此。九十多個專家組和製藥公司團隊日以繼夜地工作，為歷史上首次冠狀病毒流感制定潛在的預防措施。然而，什麼是疫苗？它們安全嗎？又是什麼使研發過程如此艱難？
I like to think vaccinations as a military drill. Human’s immune system is very complex, involving the innate and adaptive immune system. The innate immune system is what we are born with, such as the skin acting as a barrier to prevent foreign substances from invading our body. The adaptive immune system, however, will be the one where vaccinations are involved.
我喜歡將疫苗比喻為軍事演習。人類的免疫系統非常複雜，涉及先天性和後天免疫系統。天生的免疫系統就是我們出生自帶的，例如皮膚可作為阻止病菌侵入我們身體的屏障。而疫苗接種則會在後天免疫系統裡起作用。
Adaptive immune systems are like 『experiences from a military drill』. When our body is exposed to a foreign particle, for example a virus, cells in our body will automatically trigger an alert to produce things to kill the virus. However, if our body is not familiar with a new virus, production of antibodies (what works against viruses) may take a long time, and we may die even before enough antibodies are created. Much like a war, if we do not know what type of weapons our enemy is using, they will infiltrate us before we can manage to respond.
後天免疫系統就像「從軍事演習中獲取的經驗」。當我們的身體接觸病菌，例如病毒時，我們體內的細胞會自動觸發警報，以產生可殺死病毒的物質。但是，如果我們的身體對新病毒不熟悉，抗體的產生（對病毒起作用的物質）可能會十分緩慢，並且甚至可能在產生足夠的抗體之前感染者就死亡了。這就和一場戰爭一樣，如果我們不知道敵人使用的是哪種類型的武器，他們就會在我們能夠做出反應之前侵入我們。
Hence military drills, or vaccinations come in handy. Vaccinations, in short, is a safe method to introduce these foreign particles to our body so that our immune system recognises them, and has a 『memory』 of them. Through vaccination, antibodies can be made quickly to eliminate the viruses when they invade us the second or even the third time.
這充分說明了進行『軍事演習』或者說接種疫苗的重要性。 簡而言之，接種疫苗是一種將這些病菌安全的注入人體內，以便我們的免疫系統能夠識別它們並對其進行「記憶」。 通過接種疫苗，人體能在病菌第二次甚至第三次入侵我們時更快地消除病毒。
With that being said, making a vaccine is no easy feat. There are four major class of vaccine types, with each type having two subtypes, shown in the table below.
話雖如此，製作疫苗絕非易事。疫苗有四大主要類別，而每種類型都有兩個亞型，如下表所示：
Making a vaccine is not easy. Billions will be spent on research and development of a vaccine, but a few adverse events while testing the vaccine may let all of the effort and money go to waste. Now let us look in more detail how are these vaccines different from each other and how do they work. For the sake of clarity, let us all assume coronavirus will be the subject for this vaccine.
研發疫苗並不容易。疫苗研發動輒需要數十億美元，但是在測試疫苗時發生的一些不良反應可能會使所有的努力和金錢付之東流。現在讓我們仔細看看這些疫苗之間的區別和其作用原理。為了方便闡述，讓假定冠狀病毒疫苗為的本章的主角吧。
1.Inactivated virus（滅活病毒）
As I have mentioned earlier, vaccination is essentially introducing a form of foreign particle into your body, in a controlled and safe manner. Some special treatments, such as the use of formaldehyde or heat, are being used to 『kill』 the coronavirus. When this inactivated virus is injected into our body, our immune system will respond to it and create antibodies to eliminate it. However, this type of vaccine will normally require more than one dose of injection. This is because the structure or the spike proteins (what distinguishes a foreign particle to our own cells) may be damaged whilst inactivating procedures, causing the immune response to be lower than expected. Also, the production period of this type of vaccine is also longer than the others. It is usually cultivated in sterelised chicken embryos; hence the supply of chicken embryos would be the limiting factor of productivity. Also generally viruses require time to grow, slowing down the speed of production. Sinovac and Sinopharm from China would be one of the teams focused on producing an inactivated vaccine for coronavirus. In fact, Sinovac’s vaccine, named as CoronaVac, has already been approved for emergency use since July.
正如我之前提到的，疫苗接種是以一種可控且安全的方式將某種病菌引入到您的體內。一些特殊的處理方法，例如使用甲醛或加熱，將被用來「殺死」冠狀病毒。當這種滅活病毒被注入我們的體內時，我們的免疫系統將對其做出反應並產生抗體來消除它。然而，這種疫苗通常需要注射一劑以上。這是因為在滅活的過程中，病菌的結構或其刺突蛋白（新冠病毒與人體細胞最大的差異）可能會受到破壞，從而導致不足的免疫反應。而且，這種疫苗的生產周期也比其他疫苗更長。它通常使用無菌雞胚來培養，因此，雞胚的供應將成為生產力的限制因素。病毒還需要一定的時間生長繁衍。這也降低了疫苗的生產速度。
來自中國的Sinovac(1)和Sinopharm(2)是專注於生產冠狀病毒滅活疫苗的團隊之一。自7月份以來，Sinovac的CoronaVac(3)，已在中國獲得用於緊急用途的許可。
注（1）：Sinovac，科興(NasdaqGS:SVA）
注（2）：Sinopharm，國藥集團國藥控股(1099.HK)
注（3）：當地時間11月17日，在經歷巴西暫停CoronaVac疫苗3期臨床風波的一周後，科興公司在子刊柳葉刀傳染病《The Lancet Infectious Diseases》雜誌公布了這款疫苗1/2期臨床試驗數據。從文章來看，CoronaVac在受試者中觸發了快速的免疫反應，能夠提供足夠的保護幫助受試者抵禦新冠病毒（SARS-CoV-2）。shorturl.at/tvNX2
2.Non-replecating viral vector（非補充型病毒載體）
The University of Oxford AstraZeneca, Johnson&Johnson and Gamaleya Research Institute (Russia) are some major companies trying to use chimpanzee adenovirus to develop an effective vaccine against coronavirus. They insert the genes responsible for creating spike proteins in coronavirus into the adenovirus, hoping the adenovirus will express coronavirus’s spike proteins. When this modified adenovirus is injected into the human body, our body will recognise it as coronavirus, and hence the 『military drill』 is completed. The adenovirus will also be modified so that humans will not display any symptoms concerning adenovirus infection. One major advantage of this vaccine against RNA vaccines is the storing requirements. Both Sputnik V (Russia’s vaccine) and University of Oxford/AstraZeneca’s vaccine can be stored in regular refrigerators, while the RNA vaccines need to be stored in conditions such as -20C or even -70C.
牛津大學/阿斯利康，強生和Gamaleya Reaserch研究所（俄羅斯）是一些主要試圖使用黑猩猩腺病毒開發抗冠狀病毒的有效疫苗的公司。他們將在冠狀病毒中產生刺突蛋白的基因混入腺病毒的基因中，希望腺病毒能夠產生冠狀病毒的刺突蛋白。當這種改造後的腺病毒被注入人體後，我們的身體會將其識別為冠狀病毒，從而進行「軍事演習」。因為腺病毒也將經過特殊處理，所以人類不會出現腺病毒感染的症狀。這種疫苗相較於RNA疫苗的主要優勢是在儲存要求上。Sputnik V(4)（俄羅斯的疫苗）和牛津大學/阿斯利康的疫苗都可以存儲在常規冰箱中，而RNA疫苗則需要存儲在-20°C甚至-70°C的條件下。
注（4）：不甘於後？俄羅斯表示「SputnikV」新冠疫苗 有效率92％ shorturl.at/dlEX5
3.RNA Vaccine（RNA疫苗）
Nucleic acid vaccines are relatively new concepts and there are currently no approved RNA vaccines, aside from the coronavirus vaccine developed by Pfizer/BioNTech. Pfizer’s vaccine was approved by multiple countries, including the UK in early December. RNA vaccines is in someway similar to non-replicating viral vector. Instead of using an alternative virus to express spike proteins, RNA vaccines can manage to insert a section of gene responsible to express spike proteins into human cells, hence triggering an immune response. By using our own cells as a medium, there are no concerns regarding the side effects the viral vectors may cause. This vaccine is also easy to produce, as we only need to obtain the virus’s genetic material. This may also be one of the reasons why RNA vaccines were released into clinical trails quicker than any other vaccines.
核酸疫苗是一個較新的概念，除了由輝瑞公司/ BioNTech聯合開發的冠狀病毒疫苗外，目前市場上是沒有其他獲批准的RNA疫苗。輝瑞的疫苗已於12月初獲得包括英國在內的多個國家批准使用。
RNA疫苗在某種程度上類似於非複製型病毒載體疫苗。RNA疫苗無需使用其他載體來表達刺突蛋白。這個疫苗設法將負責表達刺突蛋白的基因注入人體細胞，從而觸發免疫反應。因為使用自身的細胞作為載體，我們無需擔心病毒載體所可能帶來的副作用。這種疫苗也較容易生產，因為我們只需要獲取病毒的基因即可。這也可能是RNA疫苗比其他任何疫苗都能更快地進入臨床試驗的原因之一。
4.Protein Subunits（蛋白質亞基）
One of the examples of protein subunit vaccines are hepatitis B vaccines. In the case of coronavirus, spike proteins are harvested from a culture and injected into our body directly, hoping that it will trigger an immune response. This form of vaccine generally require multiple doses to boost its effect, as often immune responses will be weak. A total of twenty-eight teams are working on this type of vaccine, but as far as we know, only the AnHui ZhiFei Longcom Biopharmaceutical + Institute of Microbiology, Chinese Academy of Sciences managed to proceed into phase three of clinical trails.
蛋白質亞單位疫苗的例子之一是B型肝炎疫苗。以冠狀病毒作為例子，我們需從培養物中收穫刺突蛋白並直接注射到我們的體內，並希望它會觸發免疫反應。這種形式的疫苗通常需要多次注射才能增強其效果，因為通常所造成的免疫反應較弱。
目前共有28個研究小組正在開發這種疫苗，但據我們所知，只有中國科學院安徽智飛龍科馬生物製藥以及中國微生物研究所成功地進入了臨床試驗的第三階段。
題外話：Effect of vaccine on stock market
疫苗對股市的影響
（特邀評論：小句號）
*20年由於疫情導致的實體經濟萎縮，2月的A股大恐慌、3月份美股多次熔斷、4月份的全球貨幣大放水等等太多消息，告訴我們疫情對於股市的影響，疫情加速了各個行業中的數位化轉型，科技股大放異彩，疫苗的研發對於股票市場的影響是非常巨大的，疫苗進展飛速，疫情在開始逐漸穩定。
*疫苗的接種陸續推行，疫苗運輸即世界範圍內開始了，航空運輸、海運股票也會水漲船高。
*新能源、光伏板塊、遠程會議、遠程醫療、電子商務等行業趨勢會繼續加速普及，後續相關股票也會上漲。
*疫苗股近期由於病毒變異也進行了一波下跌，也出現了部分股票下跌，醫療冷鏈行業也遭受到了影響。
想要了解更多，可掃描下方二維碼入群
👇
本期英文作者：奧然 Aaron
翻譯：豬豬Chloe
校對：辛夷
感謝閱讀！