“For people who are vaccinated, the virus poses little risk: a complete series of polio immunization is more than ninety-nine-per-cent protective against systemic disease. Because ninety-three per cent of children in the U.S. are vaccinated—well above the threshold for herd immunity—we won’t see anything like the horrifying twentieth-century outbreaks that paralyzed thousands of Americans each year. Still, in communities with low immunization rates, the virus could cause considerable, completely avoidable damage.” The New Yorker: The Preventable Tragedy of Polio in New York.

+ Diseases are complex. So are preventions. Polio in US, UK and Israel reveals rare risk of oral vaccine.