This bivalent vaccine targets both the original strain of the virus and the Omicron variants BA.4/BA.5, which are most of the currently circulating variants.
Ashish Jha expects this updated vaccine should be available next month.
Note this is the booster. Unvaccinated people will still have to receive their primary vaccine series using the original strain.
We can't be certain that these Omicron sub-variants won't be displaced in the future. That's the argument around having the original strain in the combination.
Any future variants will have some epitopes with the original virus. There's some future-proofing there. As an example, consider how Omicron came out of nowhere to displace Delta, Alpha, and Beta to begin with, and wasn't a descendant of either of them. And another example is the major difference between BA.1 and BA.5 even though they are Omicron sub-variants.
That is why the UK is using a BA.1 bivalent vaccine.