One in 200 infections leads to paralysis. So yes it is effectively zero risk compared to non-vaccination. If you eliminate the unvaccinated population, vaccine

One in 200 infections leads to paralysis. So yes it is effectively zero risk compared to non-vaccination. If you eliminate the unvaccinated population, vaccine-derived infections are a non-issue. Which is how we addressed the problem prior to 1979 - largely due to the fact that everyone saw first had what the virus did and there was no vaccine hesitancy. But we haven't used weakened virus vaccines for polio in the last 20 years, so it's kinda moot.