When your argument is so airtight that only a wild strawman argument can be a counter argument. Nobody is saying 50 years.

Longitudinal studies can last anywhere from weeks to decades, although they tend to be at least a year long. Maybe not 50 years but 5 to 10 years is more reasonable. So what I would do when faced with a crisis is wait 10 years and do the study. You might say but what about the crisis. I say the crisis is overblown and you will see that it wasn't quite the crisis you thought it was 10 years ago.

In the meantime while the study is being done. Mandate the vaccine for nobody and avoid giving it to those under 18, pregnant women or those who may become pregnant. So if someone wants to risk the untested vaccine then they can take the risk themselves but not take it for their children or mandate others get vaccinated.

Sort of like your body your choice, of course the your body your choice crowd didn't think this about the vaccine, I do. If you don't want to wait for the study because you think it's a crisis then you can get the untested vaccine. Other people should be allowed to wait and it certainly shouldn't be given to children who can't consent without all testing.