This January, India celebrated its first year without polio. The
country that in 2010 had more than half the world’s reported
total cases—that World Health Organization (WHO) director
Margaret Chan described as having the “most tenacious reservoir”
of the paralyzing disease—was declared free of endemic polio.
Bill Gates, who has made fighting polio his foundation’s top
priority since 2011, lauded the Indian authorities and many
other groups and individuals whose collaborative efforts made
the achievement possible: “Polio can be stopped when countries
combine the right elements—political will, quality immunization
campaigns, and an entire nation’s determination. We must build
on this moment and ensure . . . that no child ever suffers from
this crippling disease again.” Even in the face of extreme
difficulty, he added, “India’s story illustrates the possibility
of tremendous progress.” India’s story is just the latest (and,
one hopes, close to final) chapter of a greater saga stretching
back through the 20th ce