If the drug breaks down rapidly in the body, yes, we can indeed know that. Then there can be no mechanism by which it can have long term effects. That's what happens with the delivered mRNA.
But out of interest, what about the people who have long-haul COVID, do we know the mechanism how they experience long term effects from the actual disease.
Would it be possible that vaccines created long-term effects in the same way?
What is the "mechanism" from the vaccine which has caused some people to get thrombocytopenia, bells palsy, temporary deafness, and other such side effects in just the short term?
But out of interest, what about the people who have long-haul COVID, do we know the mechanism how they experience long term effects from the actual disease.
Would it be possible that vaccines created long-term effects in the same way?