I appreciate your concern about keeping yourself protected from FLu this season, especially with the concern of COVID also lurking this winters.
Have you taken the Flu vaccine, that is usually around 6-070% effective in preventing flu and may have some benefits against the COVID disease too.
Get your Vit D levels tested and try to have them more than 30, closer to 50 if possible.
Also, Vit C in the form of berries, apples, oranges and other fruits may help.
Elderberry extract has been shown to have some benefits in preventing flu too.
Beyond this, regular exercise, reducing stress, staying contented and happy with meditation, breathing exercise, mindfulness may all help you stay fit too :)
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