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The 1968 influenza pandemic (the "Hong Kong flu") was a category 2 flu pandemic whose outbreak in 1968 and 1969 killed an estimated
one million people worldwide. Hong Kong flu was one of the famous influenza pandemics in history. It was caused by an
H3N2 strain of the influenza A virus, descended from
H2N2 through antigenic shift, a genetic process in which genes from multiple subtypes reassorted to form a new virus..
‘COVID-19 is often referred to as “just another flu” or even a “lesser flu”. However, there are fundamental differences between COVID-19 and flu, which are different diseases caused by different viruses. The flu, also known as influenza, is caused by influenza viruses. In contrast,
COVID-19 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which differs from influenza viruses in its structure and composition, in the way it replicates, in the range of cells that it can infect, and in the disease that it causes.
https://www.kent.ac.uk/news/society/26761/explainer-covid-19-is-not-comparable-to-flu
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