Considering I haven't been sick in over a year I'm pretty sure a mask does work. I don't wear it outside. But I do wear it when I enter someone else's house, a restaurant for carry out or the grocery store, etc. It's not 100% effective. But if everyone is wearing a mask is significantly reduces your risk of catching something from a sneeze, someone coughing or anything airborne. Now if you choose to socialize inside a crowded room with strangers for a long period of time you're going to catch something with or without a mask.