For what reasons do such a noticeable percentage of the community object to mandatory vaccination for COVID-19, when practically all of them were vaccinated for things like measles, chicken pox, when they were children?

The problem is whenever I remember that practically all anti-vaxxers would have been vaccinated as children for various things, I keep forgetting my own half-stance (and forget my legitimate reasons) that I have against vaccination, even though I intend being vaccinated to get the COVID certificate and passport, etc.