Two drugs that are used to treat asthma and allergies may offer a way to prevent a form of pneumonia that can kill up to 40 per cent of people who contract it researchers have found. Influenza pneumonia results when a flu infection spreads to alveolar air sacs deep within the lungs. Normally a flu infection does not progress that far into the lower respiratory tract but when it does the results can be deadly. If infection is severe enough and the immune response is potent enough you get injury to these cells and are no longer able to get