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After an 80-year gap, human trials of a new tuberculosis vaccine are due to
start. If the vaccine is successful it could save millions of lives each year.
TB jabs use a weakened form of the bacterium that causes the disease in
cows—Bacille Calmette-Guérin. BCG gives good protection for about
10 years but then it wears off, and booster shots have little effect. Now Helen
McShane at the John Radcliffe Hospital in Oxford is starting trials with a
modified cowpox virus that carries a TB antigen. Used as a booster after BCG,
the new vaccine should give a much better immune response, she says.