Clinical trials of MVA85A, the first new vaccine against tuberculosis in over 80 years, have begun in South Africa's Western Cape.

The recent resurgence of tuberculosis in many parts of the world - and the emergence of multidrug-resistant strains - has led to an urgent need for new preventative measures to control the disease. Currently, the only vaccine against is the BCG vaccine, first introduced in 1921. However, BCG is thought only to be effective in preventing severe forms of the disease in children, and not in adults.

A new vaccine known as MVA85A has now been developed by Dr Helen McShane and Professor Adrian Hill at the University of Oxford. MVA85A does not replace the BCG vaccine, but rather works in tandem with it. It uses the 85A antigen - a protein found in all strains of Mycobacterium tuberculosis - to boost the response of T cells already primed by the BCG vaccine.

Results of clinical trials of the vaccine to date, carried out in Oxford and in The Gambia, show the highest T-cell responses ever induced with a vaccine: the immune response was increased by up to 20 times when the booster was used.

With funding from a Wellcome Trust Strategic Translational Award and the European Commission, the vaccine has now entered phase II trials in South Africa's Western Cape - where one in 100 infants suffers from tuberculosis, despite BCG vaccination. Having been tested in adult volunteers who are HIV negative, the researchers are now testing whether the prophylactic is safe and effective in adolescents, and in adults infected with HIV, tuberculosis or both. Once the team is fully confident of the safety of the vaccine, and the strength of the immune response it induces, it will be tested in infants - first in safety and immunogenicity studies and then in a proof-of-concept efficacy trial.

If MVA85A proves to be safe and effective in these populations, the new vaccine could be ready to use within eight years.