Earlier quoted context omitted.
They are not tested long term.
Are there any vaccines in history that have caused something unexpected 10 years from injection?
https://www.muhealth.org/our-stories/how-do-we-know-covid-19...
>When new vaccines are released, the unknown side effects, if any, show up within two months of vaccination. This history goes back to at least the 1960s with the oral polio vaccine and examples continue through today.
Beyond that you have to look at this in context - the probability of being harmed by COVID-19 vaccine (including long term) vs the probability of being harmed by a COVID-19 infection (including long term). The vaccine have the lower probability of harm by a very large magnitude.