"Don't use your sleeve as a handkerchief". So, I still am not able to get my head around the logic of people sneezing into their sleeves. I work in an office of sleeve-sneezers. I also work in an office of huggers. Do you see where I'm going with this? If you have been sneezing into your sleeve, I don't want you anywhere near me, thank you very much. Have you ever seen someone sneeze into their sleeve? Often the sneeze comes on quickly, and the elbow doesn't cover it in time. The sneeze either goes over the top of the elbow, or underneath. It takes a lot of practice and a bit of training in callisthenics to get that elbow into place correctly, efficiently and on time. As an alternative, there is such a thing as Kleenex, and that wonderful invention called soap and water.
I'm no expert in how to prevent colds. I have managed to become infected with another doozy, together with an upper respiratory tract infection, which I have been prone to since I was a child. I have been really ill, and I have missed four days of work.
If you're a sleeve-sneezer, please don't hug people until your clothing has become decontaminated. The life you save may be mine.