Common Variable Immunodeficiency Support Group
Common variable immunodeficiency (CVID) is a group of 20-30 primary immunodeficiencies (PIDs) which have a common set of symptoms but with different underlying causes. CVID's underlying causes are different, but the result of these are that the body doesn't produce sufficient antibodies in response to exposure to pathogens.
I'll throw out one more "easy" one, but hopefully still good. IMO, worthwhile to call your doc just to get a recommendation and get his/her take on what to do. It can't hurt, and I think it's valuable to be proactive with this stuff.