Salk Vaccine

Articles tagged with "Salk Vaccine".

April 12, 1955: The Day That Changed History - 'Safe, Effective, and Potent'

Tags: Salk Vaccine, 1955 Announcement, Thomas Francis, Medical History

November 22, 2025

What Three Words Ended America’s Polio Terror on April 12, 1955?

“Safe, effective, and potent.” With these words at 10:20 AM EST on April 12, 1955, Dr. Thomas Francis Jr. announced to the world from University of Michigan’s Rackham Auditorium that the Salk polio vaccine was 80-90% effective in preventing paralytic polio. This historic announcement, based on trials involving over 1.8 million children, immediately ended America’s greatest childhood health terror.

The 1954 Salk Vaccine Trial: 1.8 Million Children as Polio Pioneers

Tags: Salk Vaccine, Clinical Trials, Polio, Medical History

November 22, 2025

How Did 1.8 Million Children Test the Salk Polio Vaccine in 1954?

The 1954 Salk polio vaccine field trial involved 1.8 million children across the United States and Canada, making it the largest medical trial in history. Led by epidemiologist Thomas Francis, the study tested Jonas Salk’s killed-virus vaccine against placebo, ultimately proving 80-90% effectiveness against paralytic polio and leading to the April 12, 1955 “V-Day” announcement that changed medical history.