I created one for Venetians, found in The Holds of Vendalyr. But, it's easily reworded for a general exploit.
Remarkable Vitality. You inherited the genetic disposition toward an enduring fortitude and a capacity for survival. You gain +4 to your VITAL DEFENSES.
There's also Forewarned. And, Training, from the Martial Artist origin in Now, as well as any other Exploit that gives a bonus to "all three DEFENSES" were written before VITAL was added to the system. You can change all those to read "all four DEFENSES."
Finding ways to boost scores in END, fortitude, survival, and resistance help with increasing VITAL DEFENSE, too.