Some people don’t believe Covid-19 causes blood clots or heart attacks as research has shown, so they won’t believe the science regarding the vaccines.I’ve had no side effects from any of the 3 I’ve had. Also having side effects wouldn’t stop me from getting my next vaccine so I’m not sure what you mean by that. The vaccine greatly reduces your chance of getting covid and the symptoms if you do catch it - that’s the science - it’s up to you if you want to deny it.