Ditto what DBwithUC said, antibody levels don't decrease, but your humira level can be increased to counter it.
increasing your humira shots. Ask about
simponi (it's a shot just like humira is). I'd do some phone calls to your insurance and ask about
simponi costs and entvyio costs.
There are patient assistance programs for all of these medications, to help with copay costs. I'm not sure if that works with Medicare or not.