Bill Gates speaks in 2011 in New York with descendants of key figures in the fight against polio — Peter Salk, left, and Cathy Hively, granddaughter of Basil O’Connor, who helped to battle the disease through the March of Dimes.

Bill Gates speaks in 2011 in New York with descendants of key figures in the fight against polio — Peter Salk, left, and Cathy Hively, granddaughter of Basil O’Connor, who helped to battle the disease through the March of Dimes.