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Timeline

1 event

20th century

April 12, 1955★★★★★
Salk polio vaccine declared safe and effective
Results of a mass field trial show Jonas Salk's polio vaccine to be safe and effective, opening the way to mass vaccination.
ScienceDisease· United States

Data compiled from Wikipedia/Wikidata and the sources listed on each event.

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Timeline

20th century

Salk polio vaccine declared safe and effective