Thread by @chrischirp

I've been looking at latest English data by age.

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.

But cases keep going up. 3/7

We aren't seeing increases in adults. Note that most under 50s (inc many parents) haven't received a vaccine dose yet - so we'll see over next couple of weeks if we see an increase in this age group. 4/7

This is *not proof* of school transmission - but it is *consistent* with school transmission.

ONS infection survey and the Imperial REACT study will be important evidence either way. What happens in older age groups also important. 5/7

It was inevitable that there would be some increase in cases once schools opened - but how much increase is acceptable? What will happen if we add a lot more open stuff in a few weeks?

Easter holiday will help but is temporary. 6/7

I find it unbelievable that despite knowing Covid was airborne since last spring/summer, govt has done nothing to support schools improving ventilation in England in the last EIGHT months.

We could have, and still can, make schools safer. 7/7

thelancet.com/journals/lance…