3.Hong Kong flu (1968)
The flu of 1968 was a global outbreak of the influenza virus, which originated in the Asian continent. The pandemic was caused by the virus’ H3N2 subtype — suspected to have evolved from a previous influenza outbreak — in 1957. The virus killed one million people.
This version of the influenza virus was the H3N8 subtype, originating in the Russian Empire and subsequently spreading across the Northern Hemisphere aided by the advent of modern transport infrastructure. The disease claimed one million lives.