>>13219704Most traditional vaccines are either inactivated or attenuated vaccines. There are more, but those are the most important to understand.
Inactivated vaccines are severely weakened versions of the micro-organism that are considered inactive. The process of figuring out how much you can destroy the micro-organism while still getting the immune benefit is difficult.
Attenuated vaccines are specially cultivated versions of the micro-organisms in particular that happen to be bred to be far less damaging. Or, they use a related virus. You just want them to be enough to create an immune response, so you can fight the real virus when you encounter it. This can take quite a lot of time and testing.
mRNA vaccines do not need to use bred or inactivated whole micro-organisms. Instead, you can take a unique portion of the virus and use that instead. Virus's reproduce using your cells. They hijack the cell, inject their RNA and DNA, and use the cell to make more of themselves. Eventually, the cell bursts, and these virus's go on to infect other cells. The idea behind an mRNA vaccine is to just have your cells produce a single unique part of the virus by injecting specific mRNA instead of a whole organism.
