The BBC article doesn't explain what "wild" means in detail. This NPR article does: > And there's another type of polio that's problematic. Sixteen African nat

The BBC article doesn't explain what "wild" means in detail. This NPR article does: > And there's another type of polio that's problematic. Sixteen African nations are currently battling outbreaks of what's called "vaccine-derived polio." This is a form of polio that stems from the oral polio vaccine used in lower income countries because it is cheap and easy to administer. > The oral vaccine contains a live but weakened version of the polio virus. The virus replicates inside the child's intestine and eventually is excreted. In places with poor sanitation, fecal matter can enter the drinking water supply and the virus is able to start spreading from person to person. https://www.npr.org/sections/goatsandsoda/2020/08/25/905884740/africa-declares-wild-polio-is-wiped-out-yet-it-persists-in-vaccine-derived-cases https://www.npr.org/sections/goatsandsoda/2020/08/25/9058847...