Unlikely, there are a lot of things people and politicians believe that are mainstream.

Government officials aren't health experts. Even numerous health experts are ignorant towards vaccines possibly having limited effects and/or even being dangerous in certain cases. Both mainstream and conservative mainstream are pushing disinformation, so it's hard to figure out the truth.

Academic studies are slightly more reliable, but there are certain respected journals (e.g. BMJ) that seem to be compromised by intelligence and there are also government-linked shills in the academic field.

However, a large majority of people believe in mainstream narratives. If you say there's propaganda and disinformation surrounding the Holocaust, most people will deny it and say you're crazy. That doesn't make them controlled opposition.