Asian flu pandemic

The Asian flu pandemic was a worldwide outbreak of influenza A(H2N2) that began in 1957 and caused an estimated one to two million deaths.

Connect

Influenza A virus subtype H2N2: An influenza A virus subtype with H2 hemagglutinin and N2 neuraminidase, responsible for the 1957–1958 pandemic. This was the pandemic strain that infected people worldwide.
Guizhou: A province in southwestern China. Early reports traced the 1957 outbreak to Guizhou before it spread internationally.
Pandemic severity: The scale of illness and death caused by a pandemic, shaped by the pathogen and population vulnerability. H2N2 caused substantial global mortality, though estimates are lower than for 1918.
Hong Kong flu: The 1968 influenza pandemic caused by an H3N2 virus that spread worldwide. It followed the Asian flu and involved a different influenza subtype.
Antigenic shift: A major change in influenza virus surface antigens, often caused by reassortment of genome segments. Reassortment produced the novel H2N2 strain against which most people lacked immunity.
Influenza pandemic: An epidemic of influenza that spreads across countries or continents and affects many people. The Asian flu is one episode in the broader history of influenza pandemics.
Excess mortality: Deaths above the number expected for a population during a specified period. This measure helps estimate the pandemic's global death toll despite incomplete reporting.
Swine flu: Influenza caused by viruses circulating in pigs, including the H1N1 strain behind the 2009 pandemic. The 2009 pandemic arose from a different lineage and animal-human transmission history.
Viral reassortment: The exchange of genome segments between viruses infecting the same cell. The pandemic virus combined genetic material from human and avian influenza viruses.
Avian influenza: Influenza A viruses adapted primarily to birds, some of which can infect other species. The pandemic strain acquired avian-virus genes through reassortment.