One of the most juicy hypothesis about this is that it was the subject of some of the 'deepest' and most advanced forms of propaganda. That would also imply that it is one of the highest priority projects of those who control the levers of propaganda.
I'll be honest and say that in spite of spending a fair amount of energy entertaining this hypothesis and looking for evidence, I really have not found anything which accounts for the strength which which people hold the aforementioned contradictory belief structure. Propaganda is a vast field though, and it guards it's secrets fairly well. The hypothesis has certainly not been killed by anything I've noticed.
It is not that complicated. It is a combination of fear, cognitive dissonance, and as usual the human need to feel accepted. Fear sells the vaccine. A combination of fear of looking at the horrible truth and cognitive dissonance causes people to ignore the reality of the situation. Finally just to top it off, if anyone manages to work past these two points, the fear of being ostracized keeps people's mouths shut. Additionally since people see anyone not joining the herd to be jabbed as a threat to their health, they treat any dissenters as a direct threat to their own lives. As a result, anyone who does make it through these blocks, speaks, and manages to be heard, is simply labeled as a "antivaxer" shunned as a loon, and ignored at best.
Even if you believe in a soul, at the end of the day that soul still resides in a meatship, and like any machine, the brain can be hacked or broken. No one really likes to think of themselves as a meat puppet, but at the end of the day that is what they manage to turn us all into to one degree or another. Of course people find more comfort in denying this reality than looking the horrible truth in the face. They call it "paying attention" for a reason, because it costs. Consciousness is a burden.