If mutations eventually change the spike proteins to negatively affect MABs' efficacy (almost certain), the same will hold true for vaccines. The host immune system will have a quicker time to deployment for any antibody variations, but it's a crapshoot with respect to ultimate outcome .. it may also be that lethality or transmission are affected as well. Whether negatively or positively depends on the observer's perspective.

https://www.bloomberg.com/news/articles/2020-...fauci-says