When was the flu vaccine introduced?
Influenza vaccine
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Vaccination against influenza began in the 1930s with large scale availability in the United States beginning in 1945.[12][13] It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system.[14] The wholesale price in the developing world is about $5.25 USD per dose as of 2014.[15] In the United States, it costs less than $25 USD as of 2015.[16]