Influenza

3rd-level biomancy*

Casting Time: 1 action
Range: Self (30-foot cone)
Components: V, S, M (some pollen)
Duration: Concentration, up to 1 minute
Class: Cleric, Druid, Warlock

With a mighty sneeze that can be heard up to 300 feet away, you blast forth a 30-foot cone of phlegm, bad breath, and viral pathogens. Each creature in the area must make a Dexterity saving throw. On a failed save, a creature takes 3d6 poison damage and is poisoned for the duration. On a successful save, the creature takes half as much damage and isn’t poisoned. A poisoned creature can make a Constitution saving throw at the end of each of its turns, ending the effect on itself on a success.

Whilst poisoned in this way, a creature must roll a d12 at the start of each of its turns. On a 3 or lower, it is racked by a coughing fit and becomes incapacitated until the start of its next turn. Each creature within 5 feet of a creature when it becomes incapacitated in this way must succeed on a Constitution saving throw or also become poisoned in this way for the spell’s duration.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 and the value a poisoned creature must roll on the d12 to cause a coughing fit increases by 1 for each slot level above 3rd.

*can be replaced with necromancy
Source: Heliana's Guide to Monster Hunting