I am not type 1 but type 2 but I have also had a weakened immune system. However, I now take Propolis occasionally - as recommended by a medical herbalist - and this seems to have improved my general health greatly. I can't remember the last time I had a cold, and didn't accept the flu injection when offered.
Propolis is a resinous mixture that honey bees collect from tree buds, sap flows, or other botanical sources. Apparently it can strengthen the immune system.
Anyway, it might be worth considering......