The 1957–1958 Asian flu pandemic was a global pandemic of influenza A virus subtype H2N2 that originated in Guizhou in Southern China. The number of excess deaths caused by the pandemic is estimated to be 1–4 million around the world, making it one of the deadliest pandemics in history. A decade later, a reassorted viral strain H3N2 further caused the Hong Kong flu pandemic (1968–1970).