This is because little evidence is available. You are looking at vaccination as an urgent matter. But your average chances of getting infected are only one in 4 in a given year. That is an average exposure of about 250,000 microcovids per year. Since average chance also includes people who make very little precautions against infection, it is likely that your personal chances are better than average. There are some people here whose personal chances are an order of magnitude lower than average. If you calibrate it by 3-4 months it will take for vaccines to become abundant in US and coincidentally to add 3-4 months of safety data, you might conclude that rushing vaccination with whatever is available is not necessarily the safest strategy.
As for unknown unknowns, this where more data helps. mRNA vaccines with lipid nanoparticle delivery mode are not like any previous vaccines so one might want to discount any experience obtained with past vaccines.
This is because little evidence is available. You are looking at vaccination as an urgent matter. But your average chances of getting infected are only one in 4 in a given year. That is an average exposure of about 250,000 microcovids per year. Since average chance also includes people who make very little precautions against infection, it is likely that your personal chances are better than average. There are some people here whose personal chances are an order of magnitude lower than average. If you calibrate it by 3-4 months it will take for vaccines to become abundant in US and coincidentally to add 3-4 months of safety data, you might conclude that rushing vaccination with whatever is available is not necessarily the safest strategy.
As for unknown unknowns, this where more data helps. mRNA vaccines with lipid nanoparticle delivery mode are not like any previous vaccines so one might want to discount any experience obtained with past vaccines.