I'm familiar with the basic principles by which the moderna/pfizer vaccines work. I'm confused about how the vaccines are able to make sure that mRNA is only taken up by dendritic cells. If mRNA is taken up by unintended cells, they will also produce the viral spike protein. We definitely don't want this. We wouldn't want to trigger an immune response to random cells in our body.
Why is the mRNA not taken up by many types of cells? Will non-immune cells taken them up and display the spike protein? How do we know?
Another question is I have is the degradation time of the mRNA. Normally mRNA degrades soon after it is transcribed but wouldn't the lipid nanoparticle drug delivery coating delay this? If the spike protein is being displayed by cells for long after antibodies are already produced this could lead to unwanted symptoms.
Source that only dendritic cells take up the mRNA: https://en.wikipedia.org/wiki/RNA_vaccine#Mechanism https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3597572/