Modifying a live virus in a vaccine to be just strong enough

By genetically tweaking the constituent live virus, scientists have created a vaccine against influenza in which the virus is capable of activating the immune system but cannot replicate in healthy cells — an approach that may become more widely used for generating live virus vaccines adapted to other viruses….

By genetically tweaking the constituent live virus, scientists have created a vaccine against influenza in which the virus is capable of activating the immune system but cannot replicate in healthy cells — an approach that may become more widely used for generating live virus vaccines adapted to other viruses….