Interesting article! But, from that very article: "Despite the virus’s sluggish mutation rate, researchers have catalogued more than 12,000 mutations in SARS-C

Interesting article! But, from that very article: "Despite the virus’s sluggish mutation rate, researchers have catalogued more than 12,000 mutations in SARS-CoV-2 genomes." Now, that doesn't tell us that these mutations matter, but that's because we don't know which ones matter. But even a rate of two single-letter mutations per month could theoretically result in 2^10 different variants in less than a year. It almost certainly won't, because many of the mutations will be the same (some parts of the genome almost certainly are more likely to mutate than others). But a rate of 2 single-letter mutations per month, is not much of a limit. The nature article you reference (for which thanks, btw) says its mutation rate is about half of influenza's. Which is, yes, less, but that's still really fast compared to almost anything that isn't influenza. Even a slow-mutating virus is still mutating fast.