Allergies are the world's leading chronic condition affecting more than one billion people.
Children living in urban environments are particularly affected and for an increasing number of people, the condition is deadly.
While weekly vaccine injections have been an option for the most afflicted, most people keep the sneezing and itchy eyes at bay with antihistamine and steroid treatment.
But now, after decades of research, a cure for some allergies is finally in sight.
Join The Cure's Dr Elizabeth Healey, as she travels to Denmark and the United States to meet the scientists growing and harvesting allergens in a bid to cure the most widespread allergies.
Source: Al Jazeera