We need to split the US up into two parts so we can do A/B testing.
As others have said, the problem of vaccines isn't that they don't work. The problem of vaccines is that they work too well. They have completely eliminated the diseases that motivated their development, so people can't imagine a world where these vaccines don't exist anymore.
We need to split the US up into two parts. One gets vaccines, the other one does not. Wait 30 years. Then the people will see the effects and then the people will understand why we should have vaccines. If the people don't see the alternative scenario, they can't see the difference that vaccines make. We need to make these differences more visual.