Experts seem to be freaking out about Nu's genome. It's far out, and also it includes some of the nastiest mutations to come up in virus evolution studies, such as this: https://www.nature.com/articles/s41564-021-00954-4

Nasty mutations here referring to solely increased binding to ace2 receptor and increased transmissibility, but not lethality afaict.

As far as I can see, we don't have any idea as yet how well current vaccines will work against this new variant, although there is reason to suspect they could be less effective.