We did a phase 1 double-blind trial to compare the safety and immunogenicity of aerosol-administered and intradermally administered MVA85A METHODS : In this phase 1 , double-blind , proof-of-concept trial , 24 eligible BCG-vaccinated healthy UK adults were randomly allocated ( 1:1 ) by sequentially numbered , sealed , opaque envelopes into two groups : aerosol MVA85A and intradermal saline placebo or intradermal MVA85A and aerosol saline placebo .