Americans haven't had to fear polio since 1979, when the disease was eradicated in the U.S. But California is experiencing a flashback to the days of sudden childhood paralysis, with reports that 20 children in the past 18 months have suffered polio-like symptoms. At least a dozen have been paralyzed in one or more limbs.
The cases span the state, from the Bay Area in the north down to San Diego. Five cases--all in children who had been vaccinated against polio--have been studied by physicians from Stanford University, who found that two of the patients tested positive for what's known as...