Almost everyone carries Candida albicans. The yeast colonizes human mucous membranes—for example, the oral mucosa and the intestine—usually silently, without causing any problems. The immune system ...

Immune system disorders in children can involve an underactive, overactive, or misdirected immune response. Main groups include immunodeficiencies, autoimmune diseases, atopic diseases, and ...

Herd immunity occurs when enough people in a group are immune to a specific infection that it cannot spread easily from person to person. Vaccination programs have been successful in creating herd ...