Washington Post (02.04.13)
The first test of Aeras’s MVA85A TB vaccine has shown it to be ineffective in preventing new infections in infants and in stopping the progression of existing infections. The researchers studied 2,800 South African infants in the rural outskirts of Cape Town. The researchers immunized 2,797 infants aged 4 months. All infants received BCG vaccines; half then received MVA854A and half received a placebo. In the vaccine group, 13 percent became infected with the TB bacterium and 2 percent developed active disease; in the placebo group, 12 percent became infected and 3 percent developed active disease. These differences were not statistically significant.
In the vaccine group, 80 percent had at least one “systemic” side effect, as did 76 percent in the placebo group. Also, 18 percent of the children in each group had a serious adverse event, and seven from the vaccine group and four from the placebo group died during the study. None of the problems were believed to result from the vaccine.
Tom Evans, Aeras’s chief scientific officer, commented that the company is disappointed that the trial did not have a positive outcome, but it does not mean that this type of vaccine would not be useful in another population.
The study, “Safety and Efficacy of MVA85A, a New Tuberculosis Vaccine, in Infants Previously Vaccinated with BCG: A Randomised, Placebo-Controlled Phase 2b Trial,” was published online in the journal The Lancet (2013; doi:10.1016/S0140-6736(13)60177-4).