My wife and I travel to Europe a lot and one or both of us used to get sick 3 to 15 days after flights. Along came First Defense. We just completed a trip to Europe on 6 flights with people coughing and sneezing all around us as usual.
We used First Defense on every flight. Result: Neither of us got sick! It’s important that you blow your nose and clear out all fluid in your nostrils with a tissue before you put First Defense on. If you don’t, the filter can get plugged by fluids in your nose.