Being active in the summer months means it is not so susceptible to Vitamin D as most flu bugs are. Sunshine is why flu and colds are largely winter phenomena. I remember living up nawth, in Michigan for a time and noticed there people talking about having “summer colds.” I suspect now it is because the sun, even in the summer is at a less direct angle and.
Yes, I agree with the more sun = more Vitamin D = less flu, in *typical* flu. However, “killer flu” seems to be far less affected by Vitamin D, at least enough to be of concern.
Just today, a newspaper article:
Drink black tea and red wine to limit flu symptoms, researchers say
https://health.spectator.co.uk/drink-black-tea-and-red-wine-to-limit-flu-symptoms-researchers-say/
From what I know about influenza and the biome, this article is punctuated with errors, false assumptions, speculation and legitimate ignorance.
It hearkens back to a story from the days of the Spanish flu, in which sweaters made by a woman in Indiana were thought to somehow prevent infection, and she was swamped with thousands of desperate requests for her personally hand-knitted sweaters.