Elvis Presley was among the most famous people of the 20th century, if not the entirety of human existence. The recording artist who had hit songs like "Suspicious Minds" and "Jailhouse Rock" spent much of the 1950s, 1960s, and 1970s as a cultural touchstone.

His celebrity was such that when Presley became the face of a campaign to inoculate the youth of America against polio, people took it seriously.

In a new article for Politico, Joanne Kenen details Presley’s unlikely advocacy for the vaccine and why it mattered. Shortly after the polio vaccine began to be administered in the U.S. in 1954, it suffered a round of damaging publicity as a result of a manufacturing error. One batch of the vaccine contained the live virus, inadvertently infecting 220,000 people, with 70,000 developing muscle weakness and 164 being paralyzed. Of those infected, 10 died.

It was a devastating blow to the vaccine effort, which suffered from public suspicion over its safety.

To help regain the public’s trust, the March of Dimes arranged for Presley to be vaccinated just before he appeared on The Ed Sullivan Show on October 28, 1956. With journalists watching, New York City Health Commissioner Leona Baumgartner held Presley’s arm while assistant commissioner Harold Fuerst delivered the injection.

Presley also recorded a public service announcement for the March of Dimes reminding people that the fight against polio was not yet over.

Did Presley singlehandedly curb the polio epidemic? No. But his influence was credited with swaying hesitant teens into getting vaccinated. There were other movements at the time, including “Salk Hops,” dances named after polio vaccine developer Jonas Salk, and even a bit of social-shaming that encouraged girls to avoid dating unvaccinated boys.

Check out the full story—including what happened to a yacht Presley bought for the March of Dimes—at Politico.

[h/t Politico]