Just been having a look at the Pfizer vaccine details to see if there's anything controversial that might set people who work in healthcare's spidey senses tingling and got down in to the weeds on how the vaccine RNA is made up. It's very clever! You have (from beginning to end)
- A 'do not destroy' signal at the start (ubiquitous in nature)
- A bit that says where the RNA should be sent in the cell (ubiquitous in all complex life from yeast onwards)
- A bit that says 'hey this is for a human protein that you need, get making' (from humans obviously)
- The SARS-COV2 spike protein code itself, slightly modified so it doesn't 'trigger' and enter cells
- A bit that says 'OK, you're done' which is ubiquitous in nature
So the only non-human bit is the spike protein itself.
The whole shebang has been slightly chemically modified to help it hang around a bit longer. If you get the old jewellers eyepiece out, you can even see the 'copy and paste' bits where you can drop a different spike protein in if you want to make a vaccine against a variant.