Contagion

Your touch inflicts a magical contagion. The target must succeed on a Constitution saving throw or take 11d8 Necrotic damage and have the Poisoned condition. Also, choose one ability when you cast the spell. While Poisoned, the target has Disadvantage on saving throws made with the chosen ability. The target must repeat the saving throw at the end of each of its turns until it gets three successes or failures. If the target succeeds on three of these saves, the spell ends on the target. If the target fails three of the saves, the spell lasts for 7 days on it. Whenever the Poisoned target receives an effect that would end the Poisoned condition, the target must succeed on a Constitution saving throw, or the Poisoned condition doesn't end on it.

Your touch inflicts disease. Make a melee spell attack against a creature within your reach. On a hit, the target is poisoned.

At the end of each of the poisoned target's turns, the target must make a Constitution saving throw. If the target succeeds on three of these saves, it is no longer poisoned, and the spell ends. If the target fails three of these saves, the target is no longer poisoned, but choose one of the diseases below. The target is subjected to the chosen disease for the spell's duration.

Since this spell induces a natural disease in its target, any effect that removes a disease or otherwise ameliorates a disease's effects apply to it.