I think further up thread someone mentioned avoiding giving calpol beforehand because it may interfere with vaccination efficacy? That isn't the case, it's advisable and will not in any way impact upon the efficacy of the vaccinations. Apologies though if I read it wrong.
It's been pointed out that immunity can wane over time or, in some cases, not work at all. This is true, there are a small number of people for whom vaccinations will not be effective. This makes herd immunity all the more vital, it makes no sense to use that as a reason to not vaccinate.
You are right, there are side effects to vaccination and again you are right that statically your baby has a much higher chance of experiencing side effects (pyrexia, malaise, rash etc.) than contracting the disease itself. Leaving you feeling that you've deliberately caused your baby unnecessary suffering. But it's the severity and short lived nature of the potential side effects (and how we can give otc medicine to relieve or reduce them) versus the potential devastating consequences of contracting any one of the diseases.
The vaccination schedule hasn't been cobbled together on a whim, it has been rigorously researched. Designed to deliver the vaccinations in the most effective and safest way possible.
Deciding to not vaccinate or play around with the schedule is in essence gambling with your baby's health.