If mutations eventually change the spike proteins

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