As to vaccines "stopping the spread", check this.

Stopping the spread means the person hadn't already been infected when they were vaccinate. It means they weren't among the very small number of people who were infected despite being vaccinated, which is a higher number if one received the J&J shot. If you were correct, there would be no need to wear masks or social distance.

A vaccine can HELP stop the spread, but doesn't guarantee anything.

And an anti-vaxxer is an anti-vaxxer. They all have some non-scientific, fearful (or downright paranoid) reasons. Unfortunately, I've had a great deal of training in pathogens and immunity, including supervising an immunization clinic at a US Air Force base hospital. Thinking that a few years will show some weird, unpredictable side effects is nuts, IMO. You're entitled to believe what you want. I'm sure there are still people who believe the MMR causes autism. Fundamentally, for me, it's not worth an argument which would be based on facts.