No one studying polio knew more than Albert Sabin, the Polish-American scientist whose vaccine against the crippling disease has been used worldwide since 1959. Sabin's oral vaccine provides lifelong immunity. It has one drawback, which Sabin, who died in 1993, fiercely disputed: In rare cases, the weakened live poliovirus in the vaccine can mutate, regain virulence, and cause polio.
Those rare mutations — one of which appears to have paralyzed a young man in Rockland County, New York, who belongs to a vaccine-resistant Hasidic Jewish community, officials there reported July 21 — have taken center stage in the global campaign to eradicate polio, the largest international public health effort in history.
