““Why had the introduction of a supposedly harmless virus carrying a gene into the liver caused such a devastating, fatal reaction? As physicians, scientists, and regulators sifted through the trial, the reasons for the failed experiment became evident. The vectors used to infect Gelsinger's cells had never been properly vetted in humans. But most important, Gelsinger's immune response to the virus should have been anticipated. Gelsinger had likely been naturally exposed to the strain of adenovirus that had been used in the gene-therapy experiment. His brisk immune response was not an aberration; it was the perfectly habitual response of a body fighting a pathogen that it had previously encountered, possibly during infection by a cold. In choosing a common human virus as their vehicle for gene delivery, gene therapists had made a crucial error of judgment: they had neglected to consider that genes were being delivered into a human body with a history, with scars, memories, and prior exposures. "How could such a beautiful thing go so, so wrong?" Paul Gelsinger had asked. We now know how: because-seeking only beauty-scientists were unprepared for catastrophe. The doctors pushing the frontiers of human medicine had forgotten to account for the common cold.””
