Ear-infection, or otitis, is one of the most common diseases affecting children. It’s a painful infection that, in some cases, impairs hearing for life. What happens is that the auditory tube might be blocked. When there is an increased pressure then you can also get a perforation to the tympanic membrane. If you have otitis too many times, then there is a risk of getting hearing loss as well. Wallenberg Clinical Scholar Kristian Riesbeck, Lund University, wants to create a vaccine against otitis. And to do this with the help of the bacteria's own weapon.