We did a phase @ double-blind trial to compare the safety and immunogenicity of aerosol-administered and intradermally administered MVA@A METHODS : In this phase @ , double-blind , proof-of-concept trial , @ eligible BCG-vaccinated healthy UK adults were randomly allocated ( @:@ ) by sequentially numbered , sealed , opaque envelopes into two groups : aerosol MVA@A and intradermal saline placebo or intradermal MVA@A and aerosol saline placebo .