My husband jokes I should wear a "haz mat" suit to my job w/young germ mops.
I use a neti-pot w/saline packets before and after going to work--or am out among the gp. I also gargle w/a mouthwash before and after work.
If I feel something coming on, I use my neti-pot up to 4 times a day.
I hate saying this because I don't want to have to eat my own words, but I haven't been sick in two years while adhereing to the above practices.