N501Y is properly neutralized by vaccination (there's a paper in Science with these data, but I don't have a link handy right now).
The deletion seems to reduce antibody neutralization, but:
- In the preprint where this was shown, only 4 convalescent sera were tested;
- The same 4 sera had large variation in neutralization activity per se;
- There is no investigation on potential impaired T cell reactivity (cellular immunity): FTR, the "mink mutation", although it exhibited slightly lower antibody neutralization, did not change the reaction of T cells to it.
