At its height in the 1940s and '50s, polio paralyzed more than 35,000 Americans every year. But thanks to vaccines as well as good hygiene and sanitation practices, polio has largely been forgotten in the developed world.
Now, even in less-developed regions, it's close to being wiped out entirely. But there are still challenges to overcome before polio can join smallpox as a virus that has been eradicated worldwide.
With the support of the World Health Organization, the Bill & Melinda Gates Foundation (a strategic partner of The Conversation US that provides funding for The Conversation internationally), Rotary International and others, public health workers and volunteers work tirelessly and in dangerous conditions to vaccinate every one of the world's children. The number of polio cases globally dropped from 350,000 in 1988 to just 37 in 2016. Thirty years ago, polio was regularly found in 125 of the world's 190 or so countries. Today, only three countries continue to see regular cases: Pakistan, Nigeria and Afghanistan.
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Of these, Pakistan is closest to becoming polio-free thanks to its persistent, innovative vaccination campaign programs. But its poor security, weak health system and lack of proper sanitation work against this effort.
The lessons infectious disease preparedness and response researchers like us are learning in Pakistan, during what's hopefully a final push against polio, will also apply elsewhere, as public health experts work to wipe out other infectious diseases around the world.