MVA85A is being trialled in a series of Phase I and II studies in the Western Cape province, South Africa, where the prevalence of tuberculosis is extremely high (annual incidence of disease ~1%). In August 2005, enrolment commenced into trial 008 and it continued until July 2006. 24 healthy TB naïve and HIV uninfected adults were vaccinated. The preliminary results of this arm of the trial were presented in Vienna (Hawkridge et al, TB Vaccines for the World; April 2006) and Paris the vaccine was shown to be safe and highly immunogenic. Enrolment into the adolescent arm of this study commenced in November 2006 once it was clear that the day 84 safety results in the adults were satisfactory.