The best part is that the entire RNA sequence of the 1918 flu has been published and is available for anyone who is interested:
http://www.sciencedaily.com/releases/2007/07/070702145610.htm
Related info: Cold dry air increases chances of flu transmission. http://www.sciencedaily.com/videos/2008/0103-does_winter_cause_the_flu.htm
From the Science Daily article: “Additionally, cold, low humidity air dries out the nasal passages and makes virus transmission more likely.”
Warm, dry indoor air also dries out the nose and throat. Don’t dry out and you’ll rarely get sick, in my experience.