Forgive my ignorance on the subject. Instead of reading studies directly, I used the opinions of doctors quoting studies to inform my opinions. If memory serves, for the first booster, it was more likely that young men would develop serious complications from the vaccine booster than if they developed covid instead. I think they were heart complications.

So if a drug is shown to be more detrimental than helpful, why is it bad to refuse it, or ask for a different drug, or for more investigation?