Description: You are being asked to participate in this research study because you have cystic fibrosis (CF) and a chronic methicillin resistant Staphylococcus aureus (MRSA) lung infection. A chronic infection is one that persists or lasts a long time and usually can’t be cured. Cystic fibrosis is an inherited disease in which there are significant problems with breathing caused by a build-up of mucus in the lungs which becomes sticky and thick, making the lungs more likely to become infected. The standard treatment for cystic fibrosis includes treatment with a variety of medications, including bronchodilators (a type of prescription medicine used to help open the airways), and antibiotics. Vancomycin is an antibiotic approved by the United States Food and Drug Administration (FDA) for the treatment of serious infections. Treatment with vancomycin is usually given in the form of an injection into a vein, also called intravenous or IV, and sometimes as a pill taken by mouth. The study sponsor (Savara) is studying a new investigational powder form of vancomycin, called AeroVanc, that can be used with a reloadable capsule inhaler. This study has two periods. Period 1 will last up to 28 weeks (including Screening) and have 9 visits; Period 2 will last up to 24 weeks but will only have 4 visits. In Period 1, you have a chance (50-50) of getting AeroVanc or placebo. In Period 2 you would be getting AeroVanc.