The drive to wipe polio from the face of the earth is in jeopardy.

Afghanistan, Nigeria and Pakistan are the only three countries left where poliovirus remains endemic. But work to put the paralyzing virus on the ropes there is in danger of failing. Cases in all three countries jumped last year.

Weak public health systems, armed conflicts and corruption have hurt vaccination efforts. Now leading public health officials have proposed an emergency plan of action to get things back on track..

"Polio eradication is at a tipping point," says a report published by the World Health Organization today. "If immunity is not raised in the three remaining countries to levels necessary to stop poliovirus transmission, polio eradication will fail."

The emergency plan calls for stepped-up vaccination campaigns in areas of all three counties where polio poses the biggest threat.

Another goal: raise more money for eradication. There's about a $1 billion shortfall in funding for eradication.

Despite setbacks, there's also been reason for hope. New cases are at an all-time low — 55 cases so far this year.

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