A landmark announcement in 1953
On this day in 1953, Jonas Salk announced a major medical breakthrough: the successful testing of a vaccine to prevent polio.
Speaking on a CBS radio broadcast, Salk revealed that his killed-virus vaccine had shown promising results after being tested on himself and his family, marking a critical step forward in the fight against one of the most feared diseases of the 20th century.
How the vaccine worked
Salk’s vaccine, known as the Inactivated Poliovirus Vaccine (IPV), used a version of the virus that had been deactivated with formaldehyde.
This meant it could safely trigger the body’s immune response and produce antibodies without causing the disease itself- an innovation that made large-scale immunisation possible.
Massive trials follow in 1954
Following the 1953 announcement, large-scale field trials began in April 1954 across the United States, Canada and Finland.
The trials involved around 1.8 million children, who became known as the “Polio Pioneers”. Of these, more than 600,000 received either the vaccine or a placebo, while over a million others were part of control groups.
The scale of the trials marked one of the largest public health experiments in history.
Proven safe and effective
On 12 April 1955, the vaccine was officially declared safe and approximately 90% effective.
The announcement triggered immediate nationwide vaccination campaigns, rapidly expanding access to the life-saving treatment.
A dramatic decline in cases
The impact was swift and profound. Polio cases in the United States dropped sharply following the introduction of the vaccine.
Within a year of widespread availability, reported cases fell to fewer than 6,000, signalling the beginning of the end for a disease that had caused widespread fear, paralysis, and death.
A legacy beyond science
Salk’s polio vaccine breakthrough is widely seen as a turning point in modern medicine, ushering in a new era of vaccination and disease prevention.
Despite the global significance of his discovery, Salk chose not to patent the vaccine, allowing it to be distributed widely and affordably.
His work continues to be credited with saving millions of lives and bringing the world closer to the eradication of polio.
Also read: Foot-and-mouth disease: 3 new cases – 49 units infected
For more videos and updates, check out our YouTube channel


