I am getting the jab soon but I have a few questions that I would like some clarity on.
1) The issue about anti-body dependent enhancement
2) Will this vaccine drive the evolution of new variants?
3) How does the mRNA vaccine spread throughout the body?

1) The issue about anti-body dependent enhancement
This is a potential long term issue whereby new variants can induce anti-body dependent enhancement and it can be fatal. This was actually observed in previous mRNA vaccines and in some cases this can only be seen 18-24 months after the initial vaccination. There is a bit of uncertainty about this issue for me.

2) Will this vaccine drive the evolution of new variants?
I think the answer is a simple yes. The reason being is that the vaccine is non-sterilizing. This means that vaccinated people can and do get infected (the vaccine reduces the severity) and therefore vaccinated people remain a reservoir for the virus. Both vaccinated and unvaccinated people thus provide selective pressure for the virus to produce new variants. However, vaccinated people will drive the evolution of variants that are less susceptible to antibodies targeting the spike protein. It will be interesting to see the spread of the lambda variant as it seems to be resistant to the vaccines. Now if this is the case then it seems to me that we will need booster shots for each resistant variant.

3) How does the mRNA vaccine spread throughout the body?
I understand that the vaccine is injected into muscles cells (usually the arm) and that the vaccine enters muscles cells to start producing the spike protein. This elicits an immune response which in turn helps provide immunity against the spike protein. Part of the process is the expression of the spike protein on the surface of the cells where the mRNA was injected. Now the spike protein itself can cause local blood clots to form and this is fine at the site of injection (e.g. sore arm). My question is does the vaccine spread to other parts of the body to cause spike protein production there? Has this been quantified? Is this dependent on how the vaccine is injected (e.g. how many arterioles and venules are nicked during the process?)? I especially want to know how much of the vaccine gets to the pulmonary capillaries to induce spike protein production there. This reason for this is that blood clot formation in these capillaries can have long term negative effects that will only be picked up in 2 to 3 years. The most important one is increased pulmonary resistance (blood flow resistance) which can cause right ventricular hypertrophy and ultimately heart failure. This is not something that can be picked easily (usually chest x-rays, but who goes for them regularly?)

If this is an issue then regular boosters can increase the chances of this happening.

I hope these are all just extremely minor and unlikely issues but I would still like to have a little more clarity on these issues.