In line with what I expected, the CDC has now shifted the booster guidance from "may" to "should" for all adults 6 months after their primary series.
It was previously that adults under 50 "may" get the booster, whereas for those over 50 it was a stronger "should" recommendation. Now this applies to all adults in an effort to increase booster uptake before Omicron spreads in the US.
Omicron likely has some immune escape, and it is hoped the booster will curb this escape as the booster can increase neutralizing antibodies and perfect the immune response in a process called affinity maturation. Immunological data in the coming weeks will let us know the extent of the immune escape.
If you have been holding off on getting a booster, now is the time to do it. An Omicron specific vaccine is likely at least a few months away.
Omicron cases in Belgium and Scotland had no connection to travel from Southern Africa indicating possible community spread. I think we will discover this week Omicron is in most countries.
Our genomic surveillance is much better than when Alpha or Delta hit. So we can be sure that Omicron isn't latently high in the US at present. But I think travel restrictions at this point aren't really going to do much.