Mutation in mink threatens vaccine efficacy (General)
And it seems that this virus mutates quite frequently. I think I remember reading during the original SARS outbreak back in the day that there are both benefits and drawbacks to a virus that mutates frequently. A benefit is that it is more likely to mutate itself out of existence, or at least mutate to where it's harmless. A drawback is that it's harder to create a vaccine for it.