Or if youhave bloodtype A, and eat too many fatty meats, will that thick, type A blood compared to the thin type O blood (with B and AB being in-between) throw clots, or give you hardening of the arteries faster (or even cancer) on a high-meat-fat - diet?
Don't forget about Michelle's horoscope and Biden's bloodtype.
The tattoo idea to prove innoculation is a good one â€” you could put it in your armpit, right next to your bloodtype.
A heart transplant where conveniently enough, both subjects have the same bloodtype.
The Nephilim would naturally live to be 120 to the 1-and-one-half power (exponent = 1.5--all human but half angel--base = 120, corresponding to the longest possible human lifespan), but by drinking blood, are able to maintain their youth indefinitely--and yes, there is a bloodtype that is immune, and their blood feedings are regulated by their codes (I did the math :)