Actually Overrun isnt far off. Its not the dynamic effects of the pressure changes its your response in clearing the blocked eustachian tubes etc and all the grunting and snorting that goes with it that forces virus laden particles back down the bronchus and oesophagus when you perform the valsalva maneuver to equalize.
We all incubate Rhinoviruses in our noses that is why First Defence works (and is proven by peer reviewed science to work).
Yes the air is filtered - have you ever seen a Pall aircraft filter being changed? I have... its disgusting. Yuk.
Suggestions to help the OP:
1) Fly Business Class. Although the air refresh rate is probably similar per cabin volume, per pax it is proportionately higher and the concentration of unwashed people lower.
2) Use a saline rinse or First Defense before you leave home
3) Get a pack of decent N95 grade masks and USE THEM. 3M 1860 or similar. Use the aluminium pinch strip to ensure they fit. Remember they deteriorate due to breath moisture after several hours so change them regularly. Dont worry about people staring at you - if you were in Asia they wouldnt give it a second thought: the Japanese wear them in public places all the time. Put it on BEFORE you enter the airport.
4) Wash you hands regularly and take alcohol gel in a small 100ml bottle. Try not to rub your eyes or other mucous membranes unless you have used it (and it has evaporated!).
5) Boost your immune system. If you have a low WBC count you will know how.
Good Luck
Last edited by Pinkman; 27th Aug 2013 at 08:23.