Local unfiltered honey. 1 teaspoon per day.

This was prescribed by my daughter's pediatrician years ago to build up tolerances for local pollen.

I've been doing this myself for several years, but I put it in my morning coffee instead of using sugar.

While it won't make you immune to everything, it helps tremendously and is cheaper in price and easier on your body than taking OTC or prescription meds.

But, the humidity and weather changes here in Texas still mess with your sinuses something fierce on some days. For that, I use Afrin Severe Congestion pump mist nose spray.