sourced story
1955Reputable sourceWell documented

The polio vaccine

On the timeline · around 1955 · The polio vaccine1940194519501955196019651970

What happened

Jonas Salk's inactivated polio vaccine was declared safe and effective after a massive field trial, as epidemics peaked worldwide.

Why it matters

It began the near-eradication of a disease that had paralyzed hundreds of thousands of children.

Sources