不活化病毒(左) : 在這些疫苗中，使用化學物質（例如甲醛）或加熱使病毒變得不具有傳染性。然而，製造它們需要從大量傳染性病毒開始。

弱化病毒(右): 傳統上，通過通過動物或人類細胞傳遞病毒，引發無法致病的突變後，病毒才能被弱化以用於疫苗。紐約 Codagenix 正與印度血清研究所合作，通過改變其遺傳密碼來削弱 SARS-CoV-2，從而降低病毒蛋白的生產效率。

Weakened virus A virus is conventionally weakened for a vaccine by being passed through animal or human cells until it picks up mutations that make it less able to cause disease. Codagenix in Farmingdale, New York, is working with the Serum Institute of India, a vaccine manufacturer in Pune, to weaken SARS-CoV-2 by altering its genetic code so that viral proteins are produced less efficiently.

Inactivated virus In these vaccines, the virus is rendered uninfectious using chemicals, such as formaldehyde, or heat. Making them, however, requires starting with large quantities of infectious virus.

複製病毒載體 (如減弱的麻疹) : 新批准的伊波拉疫苗是在細胞內複製的病毒載體疫苗的一個例子。這樣的疫苗往往是安全的，並能引起強烈的免疫反應。然而，對載體的現有免疫力可能會削弱疫苗的有效性。

非複製病毒載體 (如腺病毒) : 目前沒有獲得正式許可的疫苗使用這種技術 (AZ 跟J&J都是採取緊急授權)。沒有獲得許可的疫苗使用這種方法，但它們在基因治療方面有著悠久的歷史。可能需要加強注射以誘導持久的免疫力。美國製藥巨頭強生公司(J&J)正在研究這種方法。

Replicating viral vector (such as weakened measles) The newly approved Ebola vaccine is an example of a viral-vector vaccine that replicates within cells. Such vaccines tend to be safe and provoke a strong immune response. Existing immunity to the vector could blunt the vaccine's effectiveness, however.

Non-replicating viral vector (such as adenovirus) No licensed vaccines use this method, but they have a long history in gene therapy. Booster shots can be needed to induce long-lasting immunity. US-based drug giant Johnson & Johnson is working on this approach.

DNA 疫苗
一種稱為電穿孔的過程在細胞膜上產生孔以增加 DNA 進入細胞的吸收

RNA 疫苗
RNA 通常包裹在脂質外殼中，因此它可以進入細胞

基於 RNA 和 DNA 的疫苗安全且易於開發：生產它們只涉及製造遺傳物質，而不是病毒。目前沒有獲得正式許可的疫苗使用這種技術。( 目前 Moderna 與 BNT 都是採取緊急授權 EUA )

補充: CureVac 也是 mRNA 疫苗，但失敗。

DNA vaccine
A process called electroporation creates pores in membranes to increase uptake of DNA into a cell

RNA vaccine
RNA is often encased in a lipid coat so it can enter cells

RNA- and DNA-based vaccines are safe and easy to develop: to produce them involves making genetic material only, not the virus. But they are unproven: no licensed vaccines use this technology.

蛋白質次單元疫苗 :
28 個團隊正在研究具有病毒蛋白質亞基的疫苗，大多數團隊都專注於病毒的刺突蛋白或其關鍵部分，稱為受體結合域。類似的針對 SARS 病毒的疫苗可以保護猴子免受感染，但尚未在人體中進行過測試。為了發揮作用，這些疫苗可能需要佐劑(與疫苗一起提供的免疫刺激分子) 以及注射多次疫苗。

類病毒顆粒疫苗:
空病毒殼模仿冠狀病毒結構，但不具有傳染性，因為它們缺乏遺傳物質。五個團隊正在研究“類病毒顆粒”（VLP）疫苗，這種疫苗可以引發強烈的免疫反應，但可能難以製造。

Protein subunits : Twenty-eight teams are working on vaccines with viral protein subunits - most are focusing on the virus's spike protein or a key part of it called the receptor binding domain. Similar vaccines against the SARS virus protected monkeys against infection but haven't been tested in people. To work, these vaccines might require adjuvants – immune-stimulating molecules delivered alongside the vaccine - as well as multiple doses.

Virus-like particles : Empty virus shells mimic the coronavirus structure, but aren't infectious because they lack genetic material. Five teams are working on 'virus-like particle' (VLP) vaccines, which can trigger a strong immune response, but can be difficult to manufacture.