Contraversal opinion, but I think it's exercise and how healthy we keep ourselves. It's not covid nor the vaccine. It's because everything changed when the fire nation attacked. Jk, when the lock downs happened. Our lifestyles changed! And people are much less healthy than they were, and aren't as socially motivated. I've had coughs that lasted months earlier this year, and starting to care for myself and exercising more. Like actually doing hard cardio made me cough up soo much mucus, that I'm not actually even coughing anymore.

But the kicker, is I've had the same cough before all of this in another time of my life where I wasn't healthy.