For the first time, the number of children paralyzed by mutant strains of the polio vaccine are greater than the number of children paralyzed by polio itself.
So far in 2017, there have been only six cases of “wild” polio reported anywhere in the world. By “wild,” public health officials mean the disease caused by polio virus found naturally in the environment.
By contrast, there have been 21 cases of vaccine-derived polio this year. These cases look remarkably similar to regular polio. But laboratory tests show they’re caused by remnants of the oral polio vaccine that have gotten loose in the environment, mutated and regained their ability to paralyze unvaccinated children
“It’s actually an interesting conundrum. The very tool you are using for [polio] eradication is causing the problem,” says Raul Andino, a professor of microbiology at the University of California at San Francisco.