First, the good news: in a study published Jan. 25 on a preprint server, Moderna says its COVID-19 vaccine continues to protect against two of the major mutant strains of SARS-CoV-2 circulating around the world: one that was first identified in the U.K. (called B.1.1.7) and one first seen in South Africa (B.1.351). Now, the not-so-good news.