Aerosolized medications that help loosen secretions include dornase alfa and hypertonic saline. Dornase is a recombinant human deoxyribonuclease, which breaks down DNA in the sputum, thus decreasing its viscosity. Dornase alpha improves lung function and probably decreases the risk of exacerbations but there is insufficient evidence to know if it is more or less effective than other similar medications. Denufosol, an investigational drug, opens an alternative chloride channel, helping to liquefy mucus. Whether inhaled corticosteroids are useful is unclear, but stopping inhaled corticosteroid therapy is safe. There is weak evidence that corticosteroid treatment may cause harm by interfering with growth. Pneumococcal vaccination has not been studied . , there is no clear evidence from randomized controlled trials that the influenza vaccine is beneficial for people with cystic fibrosis.