The first new TB vaccine for more than 80 years has successfully come through safety trials in the UK

Oct 25 2004

The first new TB vaccine for more than 80 years has successfully come through safety trials in the UK. The vaccine, devised by a team led by Dr Helen McShane in Oxford’s Centre for Clinical Vaccinology and Tropical Medicine (CCVTM), is designed to be used in tandem with the tried and tested BCG inoculation – first introduced in 1921 – and not to replace it.

TB has been around since the time of the pharaohs and kills some two million people worldwide annually. Someone is infected every second with Mycobaterium tuberculosis, and it is present in about one-third of the world’s population, two billion people, although many do not develop the disease, which is spread by coughing or spitting.

The vaccine, called MVA85A, is a sub-unit prophylactic vaccine, that is, a vaccine which contains one protein of TB, not the complete bacterium. It was tested in Oxford, where schoolchildren no longer routinely receive BCG. The three-year study, funded by the Wellcome Trust, involved 42 adults aged 18 to 55, who were divided into three groups. The results were published in Nature Medicine.

Of two groups who had never been inoculated with BCG, one was given BCG and the other MVA85A. The third group, who had previously received BCG, was given MVA85A as a boost. In volunteers given only MVA85A the trials showed it was safe and produced a high number of T cells, which fight disease. Those who had previously had BCG and were given MVA85A revealed a far greater number of these ‘helper’ cells – in some case up to 30 times the levels produced in the other groups, some of the strongest responses ever seen in a human vaccine.

More trials of the new vaccine will now take place in the developing world, where TB is endemic. Some are already underway in The Gambia.

Dr McShane said: ‘These results are phenomenally exciting. This is one of the first major advances in the field of TB vaccines for over 80 years. We will have to carry out more trials to see if this vaccine actually stops people from contracting TB, but initial results show that MVA85A works perfectly well alongside BCG. It is safe and stimulates a strong immune response.’

Dr McShane, who works with Professor Adrian Hill at the CCTVM, said it was also feasible that MVA85A would be safe for HIV sufferers who are susceptible to TB.