People who are vaccine skeptics dont necessarily reject ALL vaccines. We may question the usefulness of a few, the risks of some others, and the timeline used to give them especially to infants and children. (Why should babies immune systems be nuked when they can wait a few years.)
We also question taking away personal freedom to say NO. Its a permanent change and it cannot be undone, damage is permanent and so is death. No retribution for it either.
Then there’s the fact that we have to trust in the morals and the competence of whoever poured the ingredients in the tube.