As a kid, I noticed that my cousin Roger walked with a significant limp. He began wearing an elevated shoe to stabilize his gait. This was a result of polio he suffered in the 1950s – a time when the disease was rampant in the United States. Effective vaccines all but eliminated US polio in the 1960s, but it’s still epidemic in 4-5 countries today. The polio-crippled children in this photo at a physical rehabilitation center in Sierra Leone, West Africa.
Since humans are the only living being infected by polio, eradication is indeed possible. Ongoing polio eradication efforts include routine immunization of infants and children, and disease surveillance with vaccination for those missed by other approaches. Assuming that worldwide polio eradication is successful, an important unanswered question is how long wild-type poliovirus can persist in the environment and continue to be a threat, requiring sustained vaccine coverage.