Africa now free of wild poliovirus, but polio threat remains
Just one case of polio is a global threat - The Japan Times
PDF) Factors Associated with Vaccine Refusal (Polio and Routine Immunization) in High-Risk Areas of Pakistan: A Matched Case-Control Study
Polio vaccine - Wikipedia
U.S. polio case sparks alarms from New York to California - Los Angeles Times
Polio concerns grow in L.A. County after N.Y. paralysis case - Los Angeles Times
With Polio's Return, Here's What Back-to-Schoolers Need to Know - KFF Health News
Do polio and smallpox present a threat?
Polio - Wikipedia
Polio vaccine - Wikipedia
How the U.S. case might tie into the global upswing in polio
India, Southeast Asia to Mark Five Years of Being Polio-free
Why eradicating polio everywhere has been so hard to crack
In Victory Against Polio, Hope for the Battle Against COVID-19
Opinion Even a Single Case of Polio Is a Threat - The New York Times
