Thread by @DavidSteadson

In Sweden, holidays will soon be over, and schools and day care will be reopening fully in 2 weeks for over 2 million children under the age of 18.

There will be no masks, no HEPA filters, no bubbles, no CO2 monitors, no quick tests, no ventilation assessments. >

While exceptions to allow for remote learning are allowed if circumstances dictate (for an individual sick child, or a school outbreak), the general advice is clear that school is back to "normal" in-person learning.>

This is based on the Swedish Public Health Authoritie's assessment, published July 19, that adult vaccinations are high, and the spread of infection is decreasing.>

folkhalsomyndigheten.se/smittskydd-ber…

In reality, from a rolling 7 day average low of approx 215 cases/day on Jul 9/10/11 cases have been increasing ever since, with the today's update putting it now at 538 - more than doubling in 3 weeks.>

This was (and is) entirely predictable. The Delta variant, which is far more transmissible than earlier variants, has been a majority of cases in the country since the end of June, and is now (week 31) well over 90% of all sequenced cases.>

Currently, R in Sweden is in the range of 1.2 to 1.4. Sweden's sporadic data releases makes this more uncertain than the CIs in this graph would suggest, but there's zero doubt i's well over 1.>

The Swedish Public Health Authority believes around 30% of kids currently have some level of immunity due to prior infection. That leaves more than 1.4 million school aged kids with no protection against delta. >

folkhalsomyndigheten.se/smittskydd-ber…

If we simply look at this population alone, an R of 1.3 and people staying at home as soon as symptomatic leads to an epidemic curve something like this, with a peak of infections in about 6 months with more than 20000 sick kids, and over half a million infected within 7 months.>

Of course, reality isn't like that. There'll be holidays, there'll be voluntary behaviour change.

But there'll also be school, and that current R of 1.3 is with no school.

The Delta variant is currently estimated to have a base R0 of at least 5, and perhaps as much as double. >

R0 though is an estimate, and varies greatly on context. You know what *increases* the risk of an infected person infecting another person? Sitting in the same room with 30 other people for 5-6 hours a day. Yup -school.
>

So what's the epidemic curve for Swedish schoolkids look like with a likely conservative R of 5?

We'll have more than half a million kids infected within a month.>

What's the real world consequences of this?

There'll be more dead kids, albeit not many.
There'll be many more hospitalisations.

But of most concern, based on official UK data, between 1 in 50 and 1 in 10 of these kids will *still* be ill 4 mths later.>
ons.gov.uk/peoplepopulati…

That's 10000-50000 *new* kids with Long Covid within a month, and the number likely to double soon after.

But that's not all. Many of these kids will take the infection home. Breakthrough infections remain rare - but this will likely seed *thousands* of them in adults.>

Thousands, probably tens of thousands of breakthrough infections means thousands more adults hospitalised and dead.

Wave 4 is coming for us, we're at the foothills right now, but it is *100% predictable*>

Now, are my tweets above a prediction of what's going to happen? No. As the saying goes, all models are wrong, some are useful. Geography alone will slow things.

It is however a warning. >

What I *think* will happen is that the case data in the next 2 weeks will get the attention of the Swedish health authorities. The current plan was for Sweden to move to "level 1" relaxation of restrictions at the beginning of September. >

Moving to that level is only recommended if cases are less than 50/14 days/100000 population. We exceeded that more than a week ago, and cases continue to climb.>

There will, if Sweden follows their own guidelines (experience says that's no guarantee!) be no further opening up.

Schools I believe will however open as planned - and within 1-2 weeks there will begin to be significant outbreaks. >

Families will react, schools will react. Eventually, Swedish authorities will react. They will have no choice.

The question is - why wait? It's 100% predictable. We have 20 months of data on SARS-CoV-2 and now months of data on delta.

**None of this is complicated.**
>

If schools are to reopen as normal in 2 weeks, Sweden needs to take immediate action.

1. Vaccinations need to begin immediately on kids from age 12. Multiple vaccines are approved for this age group, and they are available. Use them.

euractiv.com/section/corona…

2. Masks should be recommended indoors. The CDC recommends from Kindergarten (age 2), but at *any* age will help. It's all about decreasing transmissions >

cdc.gov/coronavirus/20…

3. Schools need solid advice on ventilation and clean air. Every classroom should have a CO2 monitor installed immediately, and levels should be kept under 800ppm or better, under 500ppm. Open the damn windows, it's not winter yet!

sciencedaily.com/releases/2021/…

4. Schools should be installing HEPA filters in all classrooms. They *dramatically* decrease the concentration of aerosols. >

tandfonline.com/doi/full/10.10…

Canadian data last year indicated that schools without air purifiers had 3 to 4 times more Covid cases than schools without. And this was *before* Delta!

beta.ctvnews.ca/local/montreal…

5. Rapid tests should be in place and all kids from at least age 12, at least twice a week. Most Covid transmission occurs *before* people show symptoms. The earlier we catch infected kids, the better.

thelancet.com/journals/lanch…

This thread focuses just on kids, and as an independent population. The reality is they live amongst 8 million other Swedes. Most of them are vaccinated with at least 1 dose but as the CDC made clear last week - vaccinated people still transmit the virus.>
washingtonpost.com/context/cdc-br…

They will be infecting kids, and kids will be infecting them.

This pandemic is not over folks. Sweden, prepare for wave 4. This time it's the kids in the firing line.

@threadreaderapp unroll