Everything in moderation, even hype: learning from vaccine controversies to strike a balance with CRISPR.

The ease and applicability of CRISPR/Cas9--a new and precise gene editing and reproductive technology--have garnered hype and heightened concern about its potential 'unprecedented and horrific consequences' and have led many scientific leaders to call for a moratorium on its research and use. CRISPR appears distinctly more controversial than previous technological innovations (genetic or otherwise), with a greater reach and speed of human treatment and enhancement; however, we have seen similarly inflated hopes and fears in response to other medical innovations for well over a century. One intervention that has both historically and recently incited alarm--vaccines--serves as a pertinent example of what could go wrong if a technology's reach is shortened due to inflated fears. By comparing the vaccine controversy and the CRISPR debate, we can help separate the hype from the realistic potential of these technologies. How our society grapples with such innovations will determine the extent to which their impact on our individual and collective health will be beneficial. We must recognise the need for a tempered approach to CRISPR conversation leading to regulation and ethical application. Although CRISPR's reach will continue expanding with ongoing research, thus requiring continuous evaluation, the lessons we have learned from the vaccine controversy demonstrate that our approach must not be to shut down regulation and application now, but to thoughtfully conjoin productive debate and action so that therapeutic gene editing can alleviate suffering as soon as possible without precipitating social outcomes we would belatedly deplore. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.