What Is 'Vaccine-Derived Polio,' and How Much Should You Worry?
Polio has been nearly wiped out worldwide, but now there is a known case in the U.S. for the first time in nine years. The person is unvaccinated, but the strain they were infected with is a type of what’s called “vaccine-derived” polio. Let’s talk about what that means—because it does not mean you should avoid the…