Thread by @1goodtern

Three quick things about this year's flu wave.

Has it actually 'kicked off' yet?

Look at 2019 and 2024.
They have one kicking off point.

Interestingly it was the same week in both years - the week kids go back to school after half term break.

From there it skyrockets.

2022 in Orange kind of has two gears.
It starts off at a steady pace in August, then goes into afterburners in mid-November.

(2023 starts later in the year, but still changes gear in November)

2025 kinda follows 2022's pattern a little to start - with the early growth ahead of 2019 or 2014, but a bit more aggressively than 2022.

The question is... is it about to change up into another gear?

Because if it *does change up*, that's an even higher base to be starting from.

And as I've said elsewhere, don't be fooled by the slight apparent slowing in the last week.
Other years do the same thing before going into orbit during this second half of term.

But meanwhile, in the background, RSV is also doing *the same thing* that it did in 2022.
Leaping from nothing to lots in just a week.
It's already at 40% of the flu healthcare attendances in *just one week of growth*.

So... the ukhsa are talking about 'RSV at baseline levels', but they're doing that while looking at goofy charts like this one.

I don't think they're going to get a sense of urgency until it's too late.

RSV slammed in alongside flu in 2022 on the back of a summer of Covid.

I expect it to do exactly the same thing this year.

But going back to this one... there's an advantage and a danger to this graph that compares the different years.

By putting them all on one graph, your brain kind of looks at the outer edge of the whole block.

So unless you're deliberately directly focussing on the individual years, you just kind of see a mass of years together - in that sense it's good to be able to see the outer edge of the shape.

But it's not very good for comparing it to the shape of *individual* years.

So here it is compared with the big 2022 flu wave.

Let's hope that this one doesn't accelerate the same way.

Compared with 2019, pre-pandemic.

Do you see that this wave has two gears too?
One slight growth through the first half of term, then the acceleration after?

2023 hit much later.

Honestly, I hope that this one follows the same pattern and doesn't leap from this point.

And here's last year.

It was at this point, the first week of November, when things took off last year.

The next two weeks will provide a massive clue as to what will happen over the next two months.

But it's not just about the height of the peak.

Which of these two has more area 'under the line'?

Yeah. It's a little bit hard to tell.

But actually it's 2024.

Last year was a *worse* flu year than 2022.

So 2022 put healthcare under more pressure over a short period, but 2024 made more people ill overall.

And that's the big concern about the wave going early.

Is it going to stay high for a longer period?

Once Flu A has had its wave, are we going to get a Flu B tail like last year?

Yep.
We'll find out the hard way.