Good hygiene and vaccination combat

Dear Dr. Roach: There are a lot of flu cases in my state, and people are very worried.

My mom, a retired nurse, says that I should wash my hands several times a day for at least 20 seconds each time, including under my nails, between my fingers, and the backs of my hands, because that will also prevent colds and other respiratory illnesses.

She had to do this before entering an operating room, but this seems like overkill otherwise. Won’t a flu shot take care of any problem? — P.L.L.

Both hand-washing and the flu vaccine provide some, but incomplete, protection against the flu.

Hand-washing, done properly, can reduce the risk of developing flu by about half. That means washing your hands before and after contact with any person who might have flu; i.e., everyone. That’s an awful lot of handwashing if you are interacting with a lot of people.

Fortunately, hand sanitizers are effective and easier than the correct and effective handwashing technique your mother taught you. Still, handwashing is necessary periodically, as your hands start to feel sticky after using hand sanitizers too much. You should also wash after using the bathroom or eating.

The flu shot is also partially effective at reducing flu risk.

At the time of this writing, there is not an interim analysis of the effectiveness of this year’s flu shot: Last year it was about 47% effective.

The combination of careful hand hygiene and a flu shot might provide up to 75% protection against the flu.

Unfortunately, there is nothing that is 100% effective if you get exposed, and nearly all of us potentially get exposed during flu season.