Harvard’s Marc Lipsitch said evidence indicates that the international cordon keeping coronavirus cases bottled up in China is a leaky one, and it’s likely that the relative handful of global cases reported so far are undercounted. If true, that will lead to widespread illness internationally, including in the U.S.

Researchers have turned a CRISPR enzyme into an antiviral that can be programmed to detect and destroy RNA-based viruses in human cells.