tetano
Editor, Senior Moderator
New statistical simulations suggest that Northern Hemisphere flu pandemics are most likely to emerge in late spring or early summer at the tail end of the normal flu season, according to a new study published in PLOS Computational Biology by Spencer Fox of The University of Texas at Austin and his colleagues, Lauren Ancel Meyers (also at UT Austin) and Joel C. Miller at the Institute for Disease Modeling in Bellevue, WA.
Genetic mutations and mixing between different influenza viruses create new viral strains every year, occasionally leading to new pandemics. One might expect that the risk of a new pandemic is highest at the height of the flu season in winter, when viruses are most abundant and most likely to spread. Instead, all six flu pandemics that have occurred since 1889 emerged in spring and summer months.
Fox and his colleagues hypothesized that the late timing of flu pandemics might be caused by two opposing factors: Flu spreads best under winter environmental and social conditions. However, infection by one flu virus can provide temporary immune protection against other flu viruses, so pandemic strains cannot spread well while this temporary immunity is widespread. Together, this leaves a narrow window in the late spring and early summer for new pandemics to emerge.
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https://medicalxpress.com/news/2017-10-flu-simulations-pandemics-early-summer.html
Genetic mutations and mixing between different influenza viruses create new viral strains every year, occasionally leading to new pandemics. One might expect that the risk of a new pandemic is highest at the height of the flu season in winter, when viruses are most abundant and most likely to spread. Instead, all six flu pandemics that have occurred since 1889 emerged in spring and summer months.
Fox and his colleagues hypothesized that the late timing of flu pandemics might be caused by two opposing factors: Flu spreads best under winter environmental and social conditions. However, infection by one flu virus can provide temporary immune protection against other flu viruses, so pandemic strains cannot spread well while this temporary immunity is widespread. Together, this leaves a narrow window in the late spring and early summer for new pandemics to emerge.
...
https://medicalxpress.com/news/2017-10-flu-simulations-pandemics-early-summer.html