Different versions of the SARS-CoV-2 coronavirus are emerging. Some are spreading quickly around the world, others more slowly — but several have the public health community and researchers worried because they are behaving differently than the older version of the coronavirus. Maddie talks with NPR science correspondent Michaeleen Doucleff about the coronavirus variant first identified in the UK in late 2020 — they discuss how big of a deal it is, how vaccines may be affected, and what needs to happen to slow its spread. Email the show at shortwave@npr.org.