why polio is back

A few dozen cases in Pakistan may not seem like the biggest deal. But, in many ways, this is a race against time. The longer it takes for Pakistan to eradicate polio, the more likely it is that the disease could spread around the world.

Here’s why. Many countries have already eradicated polio. But, over time, people in those countries are likely to get lackadaisical and stop vaccinating, thinking that polio is no longer a threat. Those unvaccinated populations — including millions of children in Europe — would then be extremely susceptible to the virus if it ever entered their borders.

The World Health Organization says that it’s still on target to finish off polio for good in 2018. But that depends largely on vaccination programs in Pakistan. And if those continue to stall, the risks of a worldwide outbreak could grow.