Today I read about omission bias. That is about human inclining to avoid activity not to blame ourselves for the results.
For example if we can choose between the disease progress or to take an experimental treatment we would prefer the first one. In that case we can always say that disease was too strong. But if we choose treatment and something is going the wrong way we will have to blame ourselves and that's what people are trying to avoid.
And one more interesting thing that between two vaccines – one that can fail to protect and the other which can cause death, we will apply for the reimbursement only in second case. So even the others, even the vaccines we do not blame for doing nothing.