With that kind of a history, one doesn't take being "sick-free" for granted. I am incredibly grateful that God has kept me so healthy the last six months. Of course it's purely by His grace, but I think there are three contributing factors that have helped:
-Teaching elementary school for four years previously and working with impoverished children in Mexico for two years have helped me build some great antibodies.
-Emergen-C: I was first introduced to this by my missionary teammate Christy and her family, and it is good stuff! It comes in little packets that you dissolve in water, and one packet has 1000mg of Vitamin C plus 24 other nutrients, antioxidants, etc. I try to take it 2-3 times a week and more frequently if I think I might be getting sick. I highly recommend it, but two words of warning: Be sure you buy the brand-name and be sure to buy raspberry. Other flavors I have tried are really gross, and the Target brand is disgusting.
-Last but not least, I believe my obsession with always using hand sanitizer before I eat (and preferably washing my hands) has helped. :)