And 1960, the Koprowski vaccine was used to immunize nine million children in Poland and halted a polio outbreak there
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And 1960, the Koprowski vaccine was used to immunize nine million children in Poland and halted a polio outbreak there
Text from Wikipedia, available under CC BY-SA 4.0.
Captured 2026-08-24 from Wikipedia. The archived copy is preserved so this citation survives link rot.