And vaccine escape is non-binary as well. Variants able to do that may displace other variants, but be unable to push R0 over 1 in a largely vaccinated population. The "South African" variant B1351 can break through Pfizer, but it does seem to be controllable.[1]
A booster shot has already been developed, and I expect we'll be able to win the arms race against this virus.
[1] https://www.medrxiv.org/content/10.1101/2021.04.06.21254882v...