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In 1947, the polio vaccine was not yet available for public use; the first effective polio vaccine, developed by Jonas Salk, was introduced in 1955. However, there were experimental vaccines being tested before then. There were concerns about vaccine contamination in later years, notably in the 1950s, when some batches of the Salk vaccine were found to be contaminated with live poliovirus, leading to cases of vaccine-derived poliovirus infections.
What else can I help you with?
When Jonas salk made vaccine for polio?
yes he did it was in 1947 in Philadelphia
When did Jean Mercanton die?
Jean Mercanton died on November 4, 1947, in Paris, France of polio.
What epidemic caused schools to close in 1947?
A major flu epidemic caused by a vaccine failure was the reason many schools closed in 1947.
When was India given independence?
it was in 1947
What was the date when the women was given rite to vote in pakistan?
in 1947 they was given the rite to vote
What year was the first Tony Awards given?
1947
What day of the week was September 3 1947?
The given date was a Wednesday.
Day of the week August 5 1947?
The given date was a Tuesday.
What day of the week is February 25 1947?
The given date was a Tuesday.
What day of the week was December 18 1947?
The given date was a Thursday.
What day of the week was March 17 1947?
The given date was a Monday.
What day of the week was Sept 18 1947?
The given date was a Thursday.
