Nothing has changed about small pox or polio vaccines, so there is nothing natural about changing one’s conclusions about vaccines that have been around for decades or longer, because of the political vulnerabilities in trying to make public health recommendations on the fly during a crisis caused by a never before seen virus.

And that’s all most of it is. Politics and science simply don’t mix well. Science is never married to a conclusion, which is why even the most thoroughly tested are called theories. In politics, when we make an assertion, we move heaven and earth to never admit it’s wrong no matter how wrong it turns out to be. In science, we spare no effort trying to disprove an assertion before we call it a theory.

So, science says we turn on a dime in advising the public as new information emerges. Politics makes every example of that a gotcha moment.

The effect you are referring to is caused by good science being run through a political blender.