Picking the right virus candidate for gene therapy

Viruses often get bad press. Likened to Trojan horses they are often associated with disease. But, it is precisely because of their infectious nature that they can potentially be used as gene vectors - which are vehicles loaded with good copies of malfunctioning genes - and delivered to cells. This is difficult but even more so is penetrating the fortress of the brain. But this is exactly what gene therapy research into central nervous system diseases aims to do.