Most of today’s gene therapies rely on viruses — and that’s a problem

Will Ungerer lies in a hospital bed, next to a teddy bear, as doctor Jerry Mendell leans over him. Both are looking at the camera and smiling.

Most of today’s gene therapies rely on viruses — and that’s a problem

The next big strides in gene therapy for rare diseases may come from CRISPR and new approaches to delivery.