Hong Kong flu

The Hong Kong flu, also known as the 1968 flu pandemic, was an influenza pandemic that occurred between 1968 and 1970 and which killed between one and four million people globally. It is among the deadliest pandemics in history, and was caused by an H3N2 strain of the influenza A virus. The virus was descended from H2N2 (which caused the Asian flu pandemic in 1957–1958) through antigenic shift, a genetic process in which genes from multiple subtypes are reassorted to form a new virus.

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