For the first time since COVID struck in 2020, it is less dangerous than the seasonal flu. Like clockwork, flu viruses seem to strike more people in winter than any other season, and there are several reasons for that. The conventional wisdom used to be that flu viruses either went into a dormant state or persisted at very low levels during the summer months before flaring up again. Scientists have since figured out that, instead of simply lying low during their “off season,” the viruses also go globe-trotting, and get transmitted throughout populations all over the world. Actually, weather and climate influence the flu. It does very well in cold winter temperatures and is able to survive longer in dry air than moist air. For humans, dry air means dehydrated mucus and drier nostrils and airways, which can make it easier for the flu virus to make itself at home. Fall and winter bring a new school year and cooler outside temperatures, and more people spend more time indoors in close contact with each other, giving the flu an easy route for transmission between hosts. Thanks to all that time indoors and the short winter days, our Vitamin D decreases in the winter, and this decrease could leave us more susceptible to the flu for a few months out of the year and act as a “seasonal stimulus” for infection.
