John Burn-Murdoch Profile picture
May 27, 2021 20 tweets 7 min read Read on X
NEW: B.1617.2 is fuelling a third wave in the UK, with not only cases but also hospital admissions rising.

Vaccines will make this wave different to those that have come before, but it remains a concern, and one that other countries will soon face.

Thread on everything we know:
First, cases in the UK.

It’s been clear for some time that B.1.617.2 has been driving local outbreaks in North West of England, but data suggest it’s now far more widespread.

By mapping sequence prevalence onto total cases, we can see how the new variant is behind recent spikes
If we plot B.1.1.7 and B.1.617.2 on a common baseline, most areas show a shrinking outbreak of B.1.1.7 alongside a growing one of B.1.617.2.

What looks like "cases are flat", is probably "one going down, other going up, and it has more room to grow than the other has to shrink".
Two things to note at this point:

First, it’s not clear everywhere will follow Bolton, Blackburn, Bedford. They absolutely could (and 👀 Rossendale), but it’s also possible conditions in those areas favoured more rapid spread than elsewhere.
For example we know Bolton’s outbreak initially flared in neighbourhoods where vaccine uptake was moderately low. Pointing this out is not to blame individuals, but to demonstrate how local contexts matter in outbreaks.

Other areas e.g Sefton saw spikes become bumps.
Second thing to note, and first sign that vaccines will fundamentally change this wave:

Case rates are staying low among older, mostly-fully-vaxxed age groups

No indication this pattern is changing, and it supports evidence from @PHE_uk that two doses stand up well to B.1.617.2
And this really matters when we move onto the more critical metrics, like hospital admissions and deaths.

If you have two waves of cases of equal volume, and one has a much younger age profile, it will result in much fewer deaths.

We can use Bolton to illustrate exactly this.
Since April 1 there have 3,387 cases in Bolton. In the same length of time during last autumn’s wave, there were 3,386

But while last year 3,386 cases became an estimated 35 deaths, this year we can use age-specific-CFRs to estimate they will result in 9 deaths. A 75% reduction.
You can see the driver of that difference in expected death rate more clearly if we look only at older groups:

Although we’re looking at two periods of 3,386 cases in Bolton, the latter has far fewer cases among the elderly. 75% fewer cases among over-80s, the most vulnerable.
So the same number of cases but 75% fewer deaths, because vaccines are keeping [most of] the elderly out of this wave.

(A big thanks to @VictimOfMaths for giving my maths a sanity-check in those calcs, and to Daniel Howdon whose age-specific CFRs I used).
And it’s also worth plotting that same data for the whole of the second and third waves last year for Bolton:

The signs are that Bolton’s current outbreak is near its peak, whereas last year it was only just getting going.
Nonetheless, protecting the very elderly is only half of the battle.

Even though fatality rates are much lower for younger people, if large numbers of younger people get seriously ill, a small percentage of a large number can still cause lots of hospitalisations and some deaths.
And the data now show that hospital admissions in the UK are indeed rising. Admissions have risen by 20 per cent across the UK as a whole in the last week.

In the North West that’s 25%, and in some other regions including Scotland it’s higher still.
If we zoom in to Bolton, we can compare the recent rise in Covid hospital patients to the second wave.

That early rise looks very similar, though I would caution that last year rates kept climbing for months, this time with cases now no longer increasing that’s very unlikely.
But as with cases, it’s not enough just to look at total trends, age breakdowns matter with hospital admissions too.

And again here we see signs that this wave is not like previous waves. Thus far the rise in admissions in the North West has come exclusively among younger people
Of course, no hospital admission is a good hospital admission, and if hospitals become too full, quality of care and outcomes suffer, regardless of age.

But so far, the age profile of admissions looks promising and would again suggest a much lower fatality rate for this wave.
So in summary:
• B.1.617.2 has sent cases rising again even in a country with very good vaccine coverage
• But vaccines are keeping cases and hospital admissions largely among the younger age groups whose risk of deaths from Covid is much lower
To be clear, this is not a "so everything’s fine!" thread.

Everything is not fine, and with hospital admissions rising again it’s clear the reopening roadmap needs to be re-evaluated.

But this wave is not like the other waves, and it’s important to keep that in mind.
Finally, I said other countries will soon face this challenge.

B.1.617.2 is already dominant in India & UK (and many other Asian countries where sequence data is lacking), but prevalence also climbing fast in US, as well as many European countries.

(HT @TWenseleers for method)
What we’re seeing in UK is very likely to show up in other Western countries soon. This thread is a sign of what may come, but also a call to vaccinate, fast.

Vaccines are already making UK’s third wave less lethal. With enough jabs in arms, next country could fare even better.

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with John Burn-Murdoch

John Burn-Murdoch Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @jburnmurdoch

Nov 8
My wish for the next election is that poll trackers look like the one on the right 👉 not the left

This was yet another election where the polling showed it could easily go either way, but most of the charts just showed two nice clean lines, one leading and one trailing. Bad! Image
Pollsters and poll aggregators have gone to great lengths to emphasise the amount of uncertainty in the polls in recent weeks...

But have generally still put out charts and polling toplines that encourage people to ignore the uncertainty and focus on who’s one point ahead. Bad!
The thing about human psychology is, once you give people a nice clean number, it doesn’t matter how many times you say "but there’s an error margin of +/- x points, anything is possible".

People are going to anchor on that central number. We shouldn’t enable this behaviour!
Read 11 tweets
Nov 7
We’re going to hear lots of stories about which people, policies and rhetoric are to blame for the Democrats’ defeat.

Some of those stories may even be true!

But an underrated factor is that 2024 was an absolutely horrendous year for incumbents around the world 👇 Image
Harris lost votes, Sunak lost votes, Macron lost votes, Modi (!) lost votes, as did the Japanese, Belgian, Croatian, Bulgarian and Lithuanian governments in elections this year.

Any explanation that fails to take account for this is incomplete.

More here ft.com/content/e8ac09…
Did Biden hold on too long?

Has progressive politics alienated some Hispanic and Black men?

Yes and yes, but taking action to address those issues probably wouldn’t have produced a fundamentally different outcome.
Read 7 tweets
Oct 15
“The NHS has too many managers” latest
Many of the NHS’s difficulties can be traced back to the deep cuts in manager numbers.

Fixing this doesn’t just unblock waiting lists, it also gives doctors more time to be doctors, and alleviates the stress and poor morale that come from having to do things that aren’t your job Image
Here’s another fun NHS low hanging fruit example:

A trial last year found that by running two operating theatres side by side, they cut the time between operations from 40 minutes to 2, and were able to do a week’s worth of surgeries in one day thetimes.com/uk/article/lon…Image
Read 5 tweets
Oct 4
NEW: we may have passed peak obesity 🎉📈📉🙏

In what might be one of the most significant trends I have ever charted, the US obesity rate fell last year. Image
My column this week is about this landmark data point, and what might be behind it ft.com/content/21bd0b…
We already know from clinical trials that Ozempic and other GLP-1 drugs produce sustained reductions in body weight, but with mass public usage taking off — one in eight US adults have used the drugs — the results may now be showing up at population level. Image
Read 15 tweets
Aug 9
It’s really striking how the Corbynite left has migrated to the Greens.

The result is a curious coalition between the older and more Nimby environmentalist base, and the new hard left/progressive influx.

These are quite different people with quite different politics! Image
In 2019, one in ten Green voters was from the most progressive/left segment of voters; now that’s one in four.

Big difference in policy preferences, priorities and pressure on the leadership, as we’ve seen in e.g reaction to Denyer’s Biden statement.
The most glaring tension between these two types of Green is on decarbonisation, where the older Nimby base doesn’t want pylons *or even onshore wind farms* but many of the new progressive Green vote do.

Greens are actually less keen on wind farms than Labour and Lib Dem voters! Image
Read 8 tweets
Aug 4
That incredible Noah Lyles victory in chart form.

Lyles was in last place until *50m*, and then surged past the field to take it on the line. A blue streak.

Thompson led from 25m to 95m, but not when it counted. Image
Granular timing data via @jgault13 and the Olympics website
@jgault13 Bolt was the greatest ever, and his huge margins of victory were iconic, but this was the best men’s 100m race I’ve ever seen.
Read 6 tweets

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!

Ethereum

0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy

Bitcoin

3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us!

:(