Flu season

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Influenza (flu)
Types Avian A/H5N1 subtype Canine Equine Swine A/H1N1 subtype
Vaccines 2009 pandemic Pandemrix Live attenuated Seasonal flu vaccine brands
Treatment Amantadine Baloxavir marboxil Laninamivir Oseltamivir Peramivir Rimantadine Umifenovir Zanamivir
Pandemics 1889-1890 Russian flu 1918 Spanish flu 1957-1958 Asian flu 1968 Hong Kong flu 1977 Russian flu 2009 swine flu
Outbreaks 1976 swine flu 2006 H5N1 India 2007 Australian equine 2007 Bernard Matthews H5N1 2008 West Bengal 2015 United States H5N2 outbreak 2020–2022 H5N8 outbreak
See also Flu season Influenza evolution Influenza research Influenza-like illness Vaccine reformulations
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Flu season is an annually recurring time period characterized by the prevalence of an outbreak of influenza (flu). The season occurs during the cold half of the year in each hemisphere. It takes approximately two days to show symptoms. Influenza activity can sometimes be predicted and even tracked geographically. While the beginning of major flu activity in each season varies by location, in any specific location these minor epidemics usually take about three weeks to reach its pinnacle, and another three weeks to significantly diminish.^[1]

Annually, about 3 to 5 million cases of severe illness and 290,000 to 650,000 deaths from seasonal flu occur worldwide.^[2]