Thread by @JamesWard73

The case trends remain hard to read, but with a bit of age-group case ratio analysis, I think we can see a bit further into the fog. Let’s start with the overview: cases still falling in the under-20s and over-60s, but not the 20-60s. But that hides some important detail. 🧵

Looking first at the older (60+) age groups., we can see some very steep (and welcome) declines in the 75+, a gentle decline in the 70-74s, and gentle increases in the 60-69s. Exactly what you might expect if we were giving boosters to the most elderly first, for example.

So – good news overall. But also a reminder that if we leave the 60-69s unboosted for too long, we might see those case rates drift upwards, which would be very unhelpful.

Checking into the next group down (30-60), we also see some divergence, with the 50-somethings drifting downward, but the other ages (perhaps more influenced by high case rates in the youngsters?) still heading upwards. Could be worse, but not ideal for sure.

And finally in the under-30s, again we see different patterns. 20-29s are growing slowly, 10-19s are still falling fast (although less precipitately than a few days ago) and 0-9s are nudging back into growth – more strongly in the pre-school 0-4 group than in 5-9s.

It is perhaps instructive to look at the raw case data for the 10-14s: here we can see clearly the “missing” peak at the start of half term (due in large part to less LFD testing), but also that cases have been helpfully re-set to a new, lower level, even as testing resumes.

(note that last data-point for specimen date Monday 1st November is very incomplete, and will get revised upwards in the next couple of days – but probably shouldn’t go much above the 6,000 level).

It’s worth noting that we’re currently benefiting from the real reduced rate of child-to-child infection during half term, but that the growth trend is being artificially boosted by the resumption of testing. Whereas within a few days, those effects will swap around:

…we’ll lose the benefit of half term (as kids are already back at school infecting each other, which will show up from around Friday’s specimen date), but will also lose the testing distortion, as we start to compare days on a more like-for-like basis (from Sunday onwards).

So, turning on the crystal ball, what do I think? This is inevitably speculative, but my gut feel suggests that when the dust settles, we should see the 10-19s resume a gentle downward trend, as they started to do just before half term, and helped by a few more vaccinations.

But I wouldn’t be surprised to see the 0-9s return to growth, which might start a debate about whether, and if so how, we need to take further action to control the spread in primary schools / nurseries etc.

At the other end of the spectrum, we should see continued falls in the 75+ under the influence of boosters, which should also soon drive a stronger trend in the 70-74s and then, in due course, in the 60-69s – let’s hope the latter group won’t have risen too much before then.

The hardest groups to call are the 20-60s, as there isn’t such an obvious driver for cases to fall, or rise. I wouldn’t be surprised to see the 50-59s starting to drift up over the coming weeks, as immunity waning starts to impact, before boosters arrive.

The 30-50s will be heavily influenced by trends in kids, so perhaps we might see 30-39s rise while 40-49s fall away? (if I’ve got my forecasts right on the 0-9s and 10-19s). And the 20-29s will be mostly driven by their own behaviour – will we see more spread as winter deepens?

So, still more questions than answers, but maybe a few pointers on likely direction. Overall, I’d expect cases to fall, but not plummet. As always, admissions will be the key metric driving policy, and they’re still heading up, although that should turn in the next week. /end