https://berthub.eu/articles/posts/reverse-engineering-source-code-of-the-biontech-pfizer-vaccine/
- The CAP to make sure the RNA looks like regular mRNA
- A known successful and optimized 5' untranslated region (UTR)
- A codon optimized signal peptide to send the Spike protein to the right place (amino acids copied 100% from the original virus)
- A codon optimized version of the original spike, with two ‘Proline’ substitutions to make sure the protein appears in the right form
- A known successful and optimized 3' untranslated region
- A poly-A tail with a ‘linker’ in there
If we look closely, we see that the majority of the changes happen in the third codon position, noted with a ‘3’ above. And if we check the universal codon table, we see that this third position indeed often does not matter for which amino acid is produced.
So, the changes are synonymous, but then why are they there? Looking closely, we see that all changes except one lead to more C and Gs.
So why would you do that? As noted above, our immune system takes a very dim view of ‘exogenous’ RNA, RNA code coming from outside the cell. To evade detection, the ‘U’ in the RNA was already replaced by a Ψ.
However, it turns out that RNA with a higher amount of Gs and Cs is also converted more efficiently into proteins,
And this has been achieved in the vaccine RNA by replacing many characters with Gs and Cs wherever this was possible.
This is one of the exceptionally clever bits about the vaccine. Our body runs a powerful antivirus system (“the original one”). For this reason, cells are extremely unenthusiastic about foreign RNA and try very hard to destroy it before it does anything.
This is somewhat of a problem for our vaccine - it needs to sneak past our immune system. Over many years of experimentation, it was found that if the U in RNA is replaced by a slightly modified molecule, our immune system loses interest. For real.
So in the BioNTech/Pfizer vaccine, every U has been replaced by 1-methyl-3'-pseudouridylyl, denoted by Ψ. The really clever bit is that although this replacement Ψ placates (calms) our immune system, it is accepted as a normal U by relevant parts of the cell.
Many people have asked, could viruses also use the Ψ technique to beat our immune systems? In short, this is extremely unlikely. Life simply does not have the machinery to build 1-methyl-3'-pseudouridylyl nucleotides. Viruses rely on the machinery of life to reproduce themselves, and this facility is simply not there. The mRNA vaccines quickly degrade in the human body, and there is no possibility of the Ψ-modified RNA replicating with the Ψ still in there. “No, Really, mRNA Vaccines Are Not Going To Affect Your DNA” is also a good read.