1) Most Americans don't have the lived experience to properly weigh the value of world-changing vaccines like Polio, MMR, etc.
2) There is a strong profit motive for pharmaceutical companies to get more globally-recommended vaccines approved.
Polarizing the debate and then picking a winning side will lead to the wrong outcome. Details matter.
It takes intelligence to entertain both sides of an argument, grasp and appreciate the nuance of the situation and then come to a sensible conclusion, which is often "I don't know, I'll need to learn more to decide."
And it takes intellectual honesty to admit when our preconceptions need to be tossed and upgraded to a more expansive, more accurate worldview, which is the essense of intelligence.
That's why Dunning & Kruger's work is so damned important: It showed that the least capable are the most confident.
Realistically, you can entertain both sides of an argument and come to the conclusion that one side is wrong.
1) Establish a false dichotomy ("All vaccines are good, all vaccines are bad")
2) Come up with a pithy slur for the other side ("Antivaxx")
3) Emphasize the looniest people on the other side, ignore and hide the reasonable people on the other side.
4) Use this slur to browbeat moderates, the skeptical, the unsure and the open minded into silence.
It's very effective.