My husband and I got these for a long flight during the peak of this flu epidemic! We flew from California to Miami and it seemed like everyone on the flight was hacking and blowing their nose -- even the man in the seat directly in front of me was coughing toward his window and the wind of his cough was coming right at me behind him! (No, he didn't cover his mouth either). I can only say that my Husband and I did not catch even the slightest cold, sniffles, or anything to and from our vacation destination. Do these work? I'll trust this again for sure!