Thomas ZRM, et al. - In this phase I clinical trial, researchers ascertained if alternating aerosol and intradermal vaccination routes would boost cellular immunity to the Mycobacterium tuberculosis antigen 85A (Ag85A). This is the first human randomized clinical trial to examine heterologous prime-boost regimes utilizing aerosol and systemic routes of virally vector vaccine administration. The study sample consisted of 36 bacille Calmette-Guérin-vaccinated, healthy UK adults receiving 2 MVA85A vaccinations, test tuberculosis (TB) vaccine, 28 days apart. This investigation exhibited that the inhalation of TB vaccine was well tolerated when it was a virus made to express a TB protein and when aerosol was given the first dose of the vaccine. However, it was not well tolerated to give the first dose of the vaccine as an injection and the second dose as an inhaler 1 month later, and it will not be further developed. Inhaled vaccines stimulate blood and lung immune responses. No serious adverse events and no complications related to bronchoscopy have occurred.