BBC News Online talked to two doctors on opposite sides of the debate. A great deal of work has been done, and the evidence is overwhelming that beta interferons can reduce both the number and the severity of relapses that people with MS suffer. Trials have shown that they can reduce the number of relapses by a third on average, and some people who take the drugs actually stop having relapses completely.
Relapses can be distressing, painful and disabling.
They vary greatly in severity, but extreme attacks can result in blindness, paralysis and incontinence and may require hospitalisation. Beta interferons do not work for all MS patients, but it estimated that about half would achieve substantial relief of their symptoms by taking the drugs. Those patients for whom beta Interferons make no difference can simply be taken off the drugs. This is not an either-or situation. There are no other alternative drugs available and services such as rehabilitation or physiotherapy can never stop the progress of the disease.