What I meant is that, as well as being higher risk, the older age groups vaccination immunity was waning first so they needed the booster which might be reflected in lower hospitalisations currently. The younger age groups (maybe not as young as under 18s) will still need a booster for when their immunity wanes, whether that’s now or early next year.
I’ll rephrase what I said earlier, I think the recentish double jabbed ie under six months and boosters are maybe helping present Omicron as a milder variant