“Most American parents hardly give thought to polio beyond the instant their child is immunized against the disease. But there was a time in this country when polio paralyzed 20,000 people in a year, killing many of them,” the New York Times reports.
“Vaccines turned the tide against the virus. Over the past decade, there has been only one case in the United States, related to international travel.
”“That could change very quickly if polio vaccination rates dropped or the vaccine were to become less accessible.”