Pfizer’s CEO - Two doses of its current Covid-19 vaccine offer “very limited protection, if any

“Pfizer’s chief executive has revealed that two doses of its current Covid-19 vaccine offer “very limited protection, if any” against the Omicron variant….. Now we are working on a new version of our vaccine, the 1.1, let me put it that way, that will cover Omicron as well.”
Why are we mandating vaccines again if they don’t work for Omicron?
And by the time the Omicron version of the vaccine is released, distributed and rolled out won’t there be another strain because you know, RNA viruses are going to do what RNA viruses do and mutate.