“Will it taper out into a longer tail (perhaps a bit deeper penetration into the population by BA.2), or will it continue downward, almost flickering out?”
Every other wave in Colorado has tailed out like a bell curve as it ended. That’s what this one is doing. This wave was so steep coming down that cases would have hit zero about 10 days ago if the curve hadn’t started tailing out.
It’s completely unpredictable to me, the timing of variant appearance is unknown, and whether we will continue to catch this thing over and over is murky.
Other places that were ahead of us with their Omicron waves have especially varied on the back side of their curves.
It goes up quick everywhere, and drops quickly at first most everywhere. But some places (like the UK) have much more substantial (higher and longer) tails, while other places continue dropping quickly down to very low levels.
I tend to think that our accumulated immunity is high enough, that we will see very low levels at the end of cold and flu season (April), like we saw early last Summer (before Delta) - down another tenfold from current new case numbers.
“ whether we will continue to catch this thing over and over is murky.”
That is a big wild card. If immunity is durable, or fleeting, will make a huge difference, come next Winter.