Why do we care so much about disease that has essentially disappeared from most of the world? Because we seem to be right on the verge of wiping out polio globally, making it just the second disease to be completely eliminated from the world.
Polio cases have plummeted in the past 25 years, from an estimated 350,000 in 1988 to only 171 cases so far in 2012. But as NPR's Jackie Northam tweeted last week: For polio " 'this close' is akin to being 'kinda pregnant'. You need to eradicate polio, full stop."
To do that, kids in the most rural corners of Pakistan and Afghanistan must be inoculated, not once, but multiple times.
So how does a heat-sensitive vaccine reach mountainous villages disconnected from roads and rivers? A few months ago, UNICEF Pakistan gave us an idea of the vaccine's remarkable journey. Here's how it works.