It was a Saturday night in Albion, a small city just east of Battle Creek, Michigan, and teenagers lined up for a dance at the school gym.

The price of admission? A bared arm.

The year was 1958, and this was no ordinary Saturday night social outing: Billed as a “Salk Hop,” it was only open to young people willing to receive a jab of the polio vaccine developed by Jonas Salk, or show proof of vaccination.

The dance was part of a five-year war on polio vaccine hesitancy, a campaign that brought together the scientific know-how of public health experts with the burgeoning energy, creativity, and even sexuality of a powerful new presence in American society—teenagers.

Poliomyelitis, an infectious, virus-induced illness that could lead to paralysis, disability, and even death, didn’t become a widespread problem in the United States until the early 20th century. Before then, citizens were regularly exposed to poliovirus through unsanitary drinking water, boosting their natural immunity. Mothers also passed on immunity to their children through breast milk.

The modernization of sewage and water systems, however, meant fewer people were exposed and left children particularly vulnerable to infection. And the baby boom of the late 1940s and early 1950s set up the perfect conditions for widespread polio transmission. Suddenly, immunity was no longer a given, and tens of thousands of cases—mostly in children—began to appear every summer, possibly as a result of seasonal fluctuations in new births.

Read the full article about encouraging teens to get vaccinated by Erin Blakemore at The 74.