Both can be true. Which is why they need to do extensive tests and keep making better vaccines, and not just stick to one that worked for the disease it was trying to prevent while causing a ton of other ailments.

Would I cut off my arm because it's the best way to save my life from something that's going to kill me that's at the end of my arm (can't remember the name right now) however, I'd also want someone to be working on a solution to the issue to others won't need to cut their arms off but can instead take some medication so they can keep their arm and also not due from the thing that attacked them. If that makes any sense.?

Hippocrates was before Internet open science