An Antigen is a specialized [[protein]], though sometimes it can be a carbohydrate instead. When an antigen is injected into the bloodstream, as through vaccination, it causes the body to produce [[antibodies]]. | An Antigen is a specialized [[protein]], though sometimes it can be a carbohydrate instead. When an antigen is injected into the bloodstream, as through vaccination, it causes the body to produce [[antibodies]]. |