Following the promising results of a multiple sclerosis vaccine trial in a small group of patients, a large-scale trial has been initiated to test the efficacy of a personalized T-cell vaccine in patients with multiple sclerosis.

The vaccine, known as Tovaxin by its developers, the Texas-based company PharmaFrontiers, is now to be tested in 100 patients with multiple sclerosis. David McWilliams, of PharmaFrontiers, told BBC News that “if earlier results were replicated in this study, it might be possible to slow or even halt the progress of the condition.” (8 March 2006).

The vaccine is made from the patients' own T cells, which are cultured in the laboratory in the presence of myelin antigens that are targeted by T cells in the disease and irradiated before being returned to the patient. The hope is that an immune response is triggered against the injected myelin-reactive T cells, thereby priming the patient's immune system for elimination of the disease-causing cells. “If that's the case, the earlier we can [vaccinate] after diagnosis the better”, McWilliams told New Scientist (9 March 2006).

However, Richard Rudick of the Mellen Center for Multiple Sclerosis Treatment and Research in Cleveland, Ohio, is cautioning against over-enthusiasm for the new vaccine as “None have worked so far. This one may, but we don't know yet.” (Guardian, 9 March 2006). In addition, there is no guarantee that normal T cells will not also be eliminated following vaccination.

Nevertheless, good news might await multiple sclerosis sufferers as the US Food and Drug Administration is expected to lift its ban on prescribing natalizumab (Tysabri; Biogen Idec/Elan). Natalizumab works by blocking the migration of myelin-reactive cells to the brain, and it has been recently reported to be better than existing interferon-β treatments (The New England Journal of Medicine, 2 March 2006).