美国CDC的原文：
1. First, mRNA COVID-19 vaccines are given in the upper arm muscle or upper thigh, depending on the age of who is getting vaccinated.
2. After vaccination, the mRNA will enter the muscle cells. Once inside, they use the cells’ machinery to produce a harmless piece of what is called the spike protein. The spike protein is found on the surface of the virus that causes COVID-19. After the protein piece is made, our cells break down the mRNA and remove it, leaving the body as waste.
3. Next, our cells display the spike protein piece on their surface. Our immune system recognizes that the protein does not belong there. This triggers our immune system to produce antibodies and activate other immune cells to fight off what it thinks is an infection. This is what your body might do if you got sick with COVID-19.
4. At the end of the process, our bodies have learned how to help protect against future infection with the virus that causes COVID-19. The benefit is that people get this protection from a vaccine, without ever having to risk the potentially serious consequences of getting sick with COVID-19. Any side effects from getting the vaccine are normal signs the body is building protection.
用中文简化一下：
1. mRNA疫苗在上臂或大腿注入人体。。。
2. 接种后，mRNA会进入肌肉细胞内，利用细胞的内部机制生成一种无害的刺突蛋白，该种蛋白就是新冠病毒表面上的刺突蛋白。。。
3. 接下来，我们的细胞将刺突蛋白表达在细胞表面，我们的免疫系统发现该蛋白不属于那里，认为是一种感染，于是触发免疫反应，生成抗体并启动免疫细胞对抗它认为的感染，这也是当你真得了新冠时免疫系统所会做的。
4. 。。。。
解读重点： 1. mRNA疫苗会进入我们的细胞（这不同于任何其它疫苗）。 2. 免疫系统认为是一种感染（事实上确实是一种人为的感染），免疫系统会像对抗真正新冠感染时一样运作。（虽没明说，但众所周知，会杀掉被"感染"的细胞）。
由此可得推论： 被mRNA疫苗进入的细胞会被免疫系统杀死， 也就是说，mRNA疫苗会导致被其进入的细胞死亡。
于是问题来了：mRNA疫苗会进入我们身体哪些地方的细胞？ 答案显然是：不确定。 CDC只轻描淡写的说将进入肌肉细胞，但实际上疫苗的去向是不可控的，即使没有直接注入静脉，注射液也终究是靠静脉吸收的，先回流心脏，再被推送至全身各处。
结论： mRNA疫苗会杀伤人体细胞，mRNA疫苗对人体细胞的侵犯（进入），可能发生在全身任何地方。
本人观点： mRNA疫苗终将会被淘汰，除非应急使用，原因在于其固有的伤害性，这种伤害性至少是没必要的，S蛋白没必要在人体内制造，完全可以事先在体外制造好再注入人体，这也就是Novavax的方式。