Formulations have been developed for pulmonary delivery to treat or reduce the infectivity of diseases such as vital infections, especially tuberculosis, SARS, influenza and respiratory synticial virus in humans and hoof and mouth disease in animals. Formulations for pulmonary administration include a material that significantly alters physical properties such as surface tension and surface elasticity of lung mucus lining fluid, which may be a surfactant and, optionally, a carrier. The formulation may be administered as a powder where the particles consist basically of the material altering surface tension. The carrier may be a solution, such as an alcohol, although an aqueous solution may be utilized, or a material mixed with the material altering surface tension to form particles. These may include proteins such as albumin or polysaccharides such as dextran, which also has surface active properties, or polymers such as polyethylene oxide (PEO) or biodegradable synthetic polymers which can be used to encapsulate or deliver the materials to be delivered. Drugs, especially antivirals or antibiotics, may optionally be included with the formulation. These may be administered with or incorporated into the formulation.