The creature you touch when casting this spell becomes immune to disease for the duration. The creature can still contract and carry diseases; it simply does not suffer any effects of a disease. When exposed to a disease, the creature must make the saving throw required. If the saving throw fails, the creature becomes a carrier of the disease, and might expose others to it per the rules for the particular affliction. The creature under the effect of the spell is aware when it becomes infected. If the creature recovers from or is cured of all diseases it suffers while this spell is in effect, it continues to benefit from the spell until the spell ends. When the duration expires, the target becomes susceptible to the effect of any disease it is still carrying, as if it had just now contracted it.