Describe Medical/Vacation here.

 * 2021 chat vacine explanation {{{
1. “We look at a virus as a foreign invader that hijacks our own cells to make copies of itself and makes us sick.”

That is correct.

The key point is that during protein synthesis there is a normal cell function that takes a small fraction of the synthesized proteins and moves them to the cell membrane. These proteins are held on the outside of the cell, anchored to the membrane where the immune system can “see” them.

If the immune system “sees” a normal protein (“self”) then nothing happens.

If the immune system “sees” something new like a viral protein (“non-self”) then this triggers the initiation of an immune response.

2. “And a traditional vaccine is a deliberately weakened virus which is easily defeated by our own immune response like white blood cell "soldiers" who then learn the best way to defeat that particular viru.”

That is correct for some vaccines like measles/mumps/rubella (“attenuated vaccines”). These vaccines infect some cells and their proteins are synthesized—but don’t cause disease. The synthesized protein is transported to the outside of the membrane where the immune system “sees” them and the immune response is initiated.

Other vaccines (e.g. Hep B or DTaP) do not contain and infectious particles. Rather they provide pathogen proteins which the immune system directly “sees” without any additional synthesis of proteins. Also some vaccines like DTaP are against bacteria not virus.

3. “So instead of a weakened virus the mRNA, dressed in a fat cell suit, hops into our cells to do what exactly?
Does it prevent the cells from being able to be hijacked by the virus? Or does does it "teach" the cells how to defeat the virus?”

The mRNA is translated into one key virus protein. Since the other viral proteins are not present, the cell is not “taken over” no virus are actually made.

The one key virus protein is transported to the outside of the membrane where the immune system “sees” it and the immune response is initiated.

Later, if the patient is exposed to the virus, the immune system recognizes key viral protein and immediately starts attacking it since the vaccine has prepared it to launch an immediate and effective response.

In general the patient won’t get sick because the immune system clears the virus from the body so quickly.
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