Practical steps against flu.
1) Insure that your serum (blood) level of vitamin D is high. By this, I mean a maintenance dose of 1,000 IU each day. Importantly, some people are sensitive to oral vitamin D, and others cannot absorb it at all. But most people can.
Vitamin D has a half-dozen actions both against the virus directly, opening immune system pathways, and as an ACE inhibitor so that your immune system response is moderated. (Most flu symptoms are caused by an overreaction of the immune system.)
2) Optimal transmission of flu by coughing and sneezing happens at 40F with low humidity. The higher the temperature and humidity, the harder it is to get infected this way, so flu becomes dependent on physical contamination, most of which happens via the hands.
So during an epidemic, if you are out in public, use a goodly amount of hand sanitizer about six times a day, especially after touching objects that you suspect are contaminated. Doing so will lower your chances of getting infected that way by as much as 60%.
Otherwise, keeping the air around you warm and humid, with a humidifier, helps.
3) If people in your home have the flu and associated nausea, vomiting and diarrhea, put a gallon of bleach next to the toilet, and ask them to add a cup to the water before, or if they are in a hurry, after they use it. When a toilet is flushed, a fine water spray results which can contaminate every object in the bathroom.
4) Both Cold-Eeze and Zicam contain a form of zinc that is readily uptaken by the mucous membranes, where it inhibits viral reproduction. They taste bad, but the virus dislikes them more than you do.
“When a toilet is flushed, a fine water spray results which can contaminate every object in the bathroom.”
Which to me is the final word on the man vs. woman argument of seat up or down! (And I’m a guy).