Co-precipitates of adenovirus with metal salts

The present invention provides co-precipitates of metal salts and adenoviral vectors containing a transgene. The co-precipitates of the invention exhibit increased efficiency of gene transfer to a target cell relative to adenoviral vectors alone. Methods of making and using the co-precipitates are also provided. A method of delivering cystic fibrosis transmembrane conductance regulator to an individual with CF utilizing a co-precipitate of cationic molecules and adenoviral vectors containing a transgene encoding a CFTR protein is provided.