Was going to do a quick pre-xmas thread on where we are but SAGE minutes from their meeting yesterday covers all my points!
So here is a whistestop tour of the main bits
Omicron Growth might be slowing, but only from ~2 day doubling to ~3 day doubling. So still growing fast.
Not clear why growth is slowing: likely combo of more cautious behaviours, Plan B (e.g. work from home), moving to different age groups, more reluctance to test
Number of people in hospital with Omicron doubling every 4 to 5 days – this is rapid and so far they are younger. Also increases in transmission within hospitals. SAGE expects large increase in admissions as older people get infected over Christmas ☹
There is increasing evidence that Omicron *outcomes* are milder than Delta. How much is intrinsic to the virus, or that Omicron infects many more with vax or prev infection (with milder disease) is unclear.
Many omicron infections simply would NOT HAVE HAPPENED with Delta.
However sheer numbers of infections remain important.
For the NHS – what age groups they happen in and how much a waning booster protects against hospitalisations (hopefully a lot) is crucial.
Timing and peak of (hosp) wave depend on these factors.
The hosp peak might still be as high as previous peaks (very very bad for NHS). The sooner interventions happen to prevent infection the better - particularly if they stop older people getting infected.
DO NOT READ TOO MUCH INTO NUMBERS THIS WEEKEND.
Test seeking, test processing and data updates all go screwy over Christmas – we have to wait till next week now.
Plus the impact of Christmas mixing won’t be seen until end of the year at the very earliest.
Finally, wishing you all a happy (and safe) Christmas.
Please test regularly using LFDs and don't mix if positive OR if you have *any* cold like symptoms or otherwise feel ill.
THREAD on cases, hospital admissions and why so many scientists & NHS leaders are worried.
Case study of London - and what is behind the alarm!
1/10
The key bit is that it takes about 10-14 days from infection to needing hospital. And if you have symptoms, you'll probably test positive 4-7 days into infection.
So there's roughly a week from testing positive to becoming a hospital admission. 2/10
So - cases in London have risen *very steeply* - but *mainly* in the last week. And only in the most recent week has Omicron been dominant.
But cases to 19 Dec (incomplete!) are already more than double previous week. 3/10
Short THREAD on log scales and why I tend not to use them.
I've been criticised at times for not plotting case numbers etc on a log scale. I want to explain why.
TLDR: essentially it's because the burden of covid ill health and on NHS is people not log people. 1/8
When you've got exponential growth (e.g. in new covid cases or hospital admissions, it will be a straight line if you put the vertical axis on a "log scale" (normally equally spaced powers of 10).
Charts show same exponential growth on a normal scale and a log scale. 2/8
Log scales are really useful for e.g:
a) seeing if growth is exponential (straight line?)
b) looking for acceleration or slow down in growth
c) comparing growth between countries at different stages of epidemic 3/8
THREAD: on omicron, UK cases, London & what to do next...
Last post-briefing tweet thread of the year! 1/18
First Omicron... as of 11 December, Omicron was most common in Scotland and England but starting its growth in Wales & N Ireland. With its growth speed, shares of cases will now be much higher in all regions. 2/18
In England, UKHSA "S gene dropout" data shows it was 40% of cases by 13 DEcember. It will be dominant in England by now.
WHO first designated it a variant of concern & named it Omicron 3 weeks ago today. Crazy. 3/18
SHORT THREAD: Some basic musings about hospital admissions and exponential growth.
88K cases reported today - let's assume just under half are Omicron - so ~40K. Delta hospital admissions have been running at about 1.7% of reported cases in last month. 1/5
Let's assume Omicron was half as likely to cause hospital admission as Delta. So 0.8% of reported cases end up in hospital. From 40K cases today that would result 340 admissions.
just FOUR doublings takes you to 5,440 admissions - far higher than last January peak. 2/5
The 40K cases today represent people infected about a week ago. Omicron has been doubling every 2 days. Even if that's slowed this week to 3 days, that's likely 2 more doubling baked into admissions. That means that FROM NOW we there'd be two more doublings exceeding jan peak 3/5
Four charts about why boosters can't do everything on their own.
1. There is a massive difference in booster uptake between the most and least deprived areas. And also a massive difference in those entirely unvaccinated.
What is plan to reach them? 1/4
2. There are big regional variations. London has the highest unvaccinated and least boosted population by far. It is also where epicentre of Omicron currently sits. There are far too many vulnerable people left in London. 2/4
3. There are big age differences that will take time to smooth out - even with our current booster acceleration.
In London (below), far too many teens remain unvaccinated and far too few over 50s boosted. 3/4