You’re safe if everyone else is vaccinated – Myth
Unfortunately that’s a big if. Often, like-minded unvaccinated families by choice attend the same preschools, playgroups, and schools, thus making it very easy for vaccine-preventable diseases to spread.
And some people can’t be vaccinated due to health or age restrictions. Plus, you can catch some germs, like tetanus and hepatitis A, from contaminated soil or food, not another person.