Wasn't polio wiped out? Why it is still a problem in some countries

LONDON — Polio was eliminated from most parts of the world as part of a decadeslong effort by the World Health Organization and partners to wipe out the disease. But polio is one of the world's most infectious diseases and is still spreading in a small number of countries. The WHO and its partners want to eradicate polio in the next few years. Until it is gone from the planet, the virus will continue to trigger outbreaks anywhere children are not fully vaccinated. The recent polio infection in...