criteria for the disease, including minimum age of diagnosis and the need to exclude other conditions. since publication in 1999 some criteria have been changed, such as increasing the minimum age of diagnosis. research current research is aimed at studying large cohorts of people with cvid in an attempt to better understand age of onset, as well as mechanism, genetic factors, and progression of the disease. funding for research in the us is provided by the national institutes of health. key research in the uk was previously funded by the primary immunodeficiency association (pia) until its closure in january 2012, and funding is raised through the annual jeans for genes campaign. current efforts are aimed at studying the following: causes of complications. little is known about why such diverse complications arise during treatment. underlying genetic factors. though many polymorphisms and mutations have been identified, their respective roles in cvid development are poorly understood, and not represented in all people with cvid. finding new ways to study cvid. given that cvid arises from more than one gene, gene knock-out methods are unlikely to be helpful. it is necessary to seek out disease related polymorphisms by screening large populations of people with cvid, but this is challenging given the rarity of the disease.