The 1957 influenza pandemic (the "Asian flu") was one of the famous influenza pandemics in history.The "Asian Flu" was a category 2 flu pandemic outbreak of avian influenza that originated in China in early 1956 lasting until 1958. It originated from mutation in wild ducks combining with a pre-existing human strain. A vaccine for H2N2 was introduced in 1957, and the pandemic slowed down. There was a second wave in 1958, and H2N2 went on to become part of the regular wave of seasonal flu. In 1968, the H2N2 Asian flu disappeared from the human population and is believed to have gone extinct in the wild. Vials of H2N2 influenza remain in laboratories across the world. The 1957 pandemic influenza H2N2 Hemagglutinin (HA) proteins and antibodies were the main research tools for this influenza pandemic.
The Asian flu results in symptoms similar to many other strains of influenza, including fever, body aches, chills, cough, weakness, and loss of appetite. Asian flu causes many of the symptoms commonly reported in an influenza virus. Influenza is a respiratory illness, so a dry cough, sore throat, and difficulty breathing are all widely reported among flu sufferers. Influenza usually results in a high fever and body aches or chills. An individual might have no appetite and subsequently lose weight. Recovery from the H2N2 can take many weeks; complications include pneumonia, seizures, heart failure, and death.
The virus of Asian flu was first identified in Guizhou. It spread to Singapore in February 1957, reached Hong Kong by April, and US by June. Death toll in the US was approximately 69,800. The elderly were particularly vulnerable. Estimates of worldwide deaths vary widely depending on source, ranging from 1 million to 4 million,with WHO settling on "about two million".