In a phase 1 clinical trial assessing the safety and immunogenicity of 1×107 plaque-forming units (pfu) of the MVA85A TB vaccine administered via inhalation or ID in 22 BCG-vaccinated adults, Ag85A-specific CD4+ T-cell responses in fluid obtained via bronchioalveolar lavage (BAL) were found to be stronger after AE than ID administration31. This evidence concerns the gene CD4 and tuberculosis.