Was a study that created a hybrid COVID-19 virus too risky?

(Science) Science looks at the furor over an experiment that combined Omicron with a more lethal SARS-CoV-2 variant. This week, Twitter exploded with outrage about a study that seemed to have created a Frankenstein COVID-19 virus: a version of SARS-CoV-2 that combines Omicron, the fast-spreading but relatively mild variant that’s now everywhere, and a deadlier strain from early in the pandemic. The labmade virus killed 80% of mice infected with it, compared with no deaths with the unmodified Omicron variant, according to a preprint posted online on 14 October by Boston University (BU) researchers.