We're seeing two different epidemics by age (thx to @dgurdasani1 for phrase).
(expand gif to see corresponding dates and whole thing) 1/4
The increase in younger children after schools go back is very obvious in Scotland (after 22 Feb) and in England (after 8 March) while decrease in older ages continues.
So vaccination & restrictions offsetting opening of schools - this is good! BUT 2/4
With the release of latest long covid estimates from ONS infection survey today as well, I still don't think we should be complacent about lots of younger people reporting long covid (10%-13%).
Was briefly on @BBCOne News @ 6 last night discussing the (excellent) findings from the ONS Covid antibody survey that came out yesterday.
Clip is here but a couple of things to add:
Having so many people with antibodies is great news and will help keep cases (and severe illness) down, but we still have millions without antibodies.
Israel is showing that opening up with high vax, masks, social distancing, test & trace keeps cases going down sharply.
Antibodies declining in older people as they approach many weeks from first dose. Does *not* mean they are no longer protected but it does mean we need to concentrate on giving people their 2nd doses. Strong case for shorter interval for very vulnerable. blogs.bmj.com/bmj/2021/03/30…
Some signs that they are spreading - slowly and from very low numbers - but spreading nonetheless.
Why I think this and what it means - let's dive in: 1/13
The Kent strain (B117) has been over 90% of cases in England since mid-Jan. It is 30-50% more transmissible than the old Covid strain and so came to dominate over about 2 months.
All existing vaccines work brilliantly against B117. 2/13
Vaccines work less well against some other Covid strains.
Particularly concerning are the South Africa (B1351) and Brazil (P1) strains.
Public Health England is tracking these (& similar) variants and doing surge testing to try to contain them.
Cases in school age children are definitely going up while other age groups are flat or falling (slowly).
Some of this increase is undoubtedly because of mass lateral flow device testing rolled out to schools. But NOT all. 1/7
*Primary* school age kids are *not* getting routinely tested - tests are still symptom based. We see little change in cases week of 8th March but we start seeing quite rapid increase 14th March onwards.
This is consistent with increased spread since schools opened. 2/7
*Secondary* school age cases started going up around 8 March - when mass testing started.
But if it was *only* mass testing, then you'd expect cases to flatten the next week (15th March onwards), as similar number of LFDs done both weeks.
The Europe wave is not coming here *because we've already have it*.
Instead, it's taken two months for our "Kent" strain (B117) to spread across the EU and start a new wave there. OLD restrictions work on the OLD strain but NOT Kent. So cases go up as soon it is dominant. 2/6
If cases start steadily going up here it will be for one of two reasons (or both!):
1) As we found out in Dec, OLD mitigations don't work on B117. But opening up with OLD mitigations relying on vaccination to help keep cases down & chaotic mass testing (esp schools). 3/6
Firstly, the current increases in Europe are because B117 (the Kent strain) has become dominant there - move than 70% in Denmark, NL, 50-70% in France, Belgium, Itlay, Germany & Austria. 2/11
As with us in Dec, they didn't act decisively to stop its spread - instead they've been in semi-restrictions (similar to our tier 3) - enough to bring *down* cases of old variant but not enough to stop B117.
It's now 4 weeks since Scotland & Wales started a phased return to primary schools (secondary schools went back last week) & 2 weeks since all schools in England went back.
What is happening? 1/15
First let's look at Wales. They started sending young kids back to nursery and primary schools 22nd Feb. Older primary school kids & secondary school went back last week.
Wales publish new Covid incidents in schools - and (unsurprisingly) incidents are increasing. 2/15
Secondly, Scotland. There we have case data by age.
Primary school kids only get a test if they get symptoms. School staff can get tested without symptoms if they want. All positive cases from lateral flow device tests (LFDs) are PCR confirmed.