Every year the bacterium, pneumococcus, causes 1 million child deaths worldwide. There is evidence that infection by a virus that causes respiratory infections in children (called respiratory syncytial virus or RSV) may increase the chance of the child being infected by pneumococcal bacteria possibly leading to life-threatening diseases such as pneumonia and meningitis.It is thought that RSV increases the likelihood of pneumococcus infection by enhancing invasion of the bacteria through cells lining the airway into the body. For example, infection by the virus may increase damage to the microscopic hairs that cover the cells lining the nose and airways of the lungs. These tiny hair-like structures normally beat at a frequency of around 12-14 beats per second and help to remove bacteria and debris from the airways.The aim of this research is to understand how the virus makes the lining of the airway more susceptible to infection by pneumococcal bacteria. Improving this understanding will enable future testing of treatments to decrease the incidence and severity of pneumococcal disease — which is ever more important in the face of increasing antibiotic resistance.