Irah completed his PhD at the University of Rochester in 2008 under the guidance of Dr. Benjamin Segal in the study of neuroimmunological diseases. His thesis work involved use of an animal model of Multiple Sclerosis, Experimental Autoimmune Encephalomyelitis, to investigate mechanisms of monocyte and dendritic cell differentiation. He then joined the Trudeau Institute as a postdoctoral fellow in the laboratory of Dr. Markus Mohrs where his research focused on the differentiation and function of T lymphocyte subsets that promote humoral immune responses to intestinal helminth infection. In 2012, he joined the department of Microbiology and Immunology at McGill University and currently is an Associate Professor and Canada Research Chair in barrier immunity studying mucosal immunology and host-parasite interactions.