I am happy to find a site where there are so many harmonica players.
I've been playing the harp for 34 years and I practice every single day and am always learning new material.
I'm looking into finding a school that has some sort of a degree program in order to be able to teach professionally.
Welcome Mike!!! Great to have you here. You can teach harmonica without a degree and get paid if you want to. If you are wanting to teach in an accredited institution of learning you will most likely need an accredited degree of some sort. Anyway, I hope you hang around and join the fun.
As Sarge says, you don't need a degree to teach harmonica. A lot of teachers do this via the web, through programmes such as Skype. Check out Adam Gussow, Jon Gindick, and others who teach through their websites.
May be worth contacting your local adult education institution. One locally here runs a course occasionally - based on demand. I don't know if they have any requirements, but a lot of these don't seem to require academic qualifications, just experience and skill.
May also be worth contacting your local music shops and discussing referrals with them.