In fact the authors note the difficulty in identifying PIMS-TS related deaths, because a diagnostic code for this was only generated in Nov 2020. Different codes were considered to represent this before, but it's very likely cases would've been missed at least early on.

For deaths from PIMS-TS, a multi-inflammatory syndrome that can occur after COVID-19, they relied on diagnoses being in the electronic record. Given this syndrome was only identified and described in April 2020, this would almost certainly have been underestimated.

It depended on a subjective review of case reports by 3 experts. All reviewers only agreed on only half of the cases they reviewed, indicating the really subjective nature of review. And consensus still could not be reached on 9 which needed further review.

"identifying whether SARS-CoV-2 was listed as 1a (the direct cause of death) on the Certificate of Cause of Death and whether the clinical course described was typical of SARS-CoV-2 infection." For the rest, a review was carried out to determine whether SARS-CoV-2 contributed.

The authors carried a review of 61 deaths in children who were positive for SARS-CoV-2/had PIMS-TS and come to the conclusion that only 25 were due to SARS-CoV-2. They conclude that only 25/61= 41% of all children who died 'with' COVID-19 died 'from' it.

The analysis is between March '20-Feb '21. Why is this important: -delta was not dominant -there were 3 lockdowns during this period None of this is relevant now with delta, no mitigations, the highest infection rates we've *ever* had in children (4-5% even post- half-term)

Ok, so worth really looking closely at the @NatureMedicine paper that's been cited widely on the impact of COVID-19 on children's deaths. This has several key limitations, and should not be cited in the way it is being

The Pfizer-BioNTech COVID-19 vaccine is associated with lower viral load in breakthrough infections, but this effect vanishes at 6 months after vaccination, according to a @NatureMedicine paper. A booster restores the reduction in viral load. https://go.nature.com/3mT9Y7V

23/ TRANSLATIONS: if interested in translating the comics, pls complete agreement in folder below, & send it to @ChiaWang8 at chiawang@mail.nsysu.edu.tw: Translation to Indonesian, Thai, Dutch, and Sinhala is already underway. Help for others needed https://drive.google.com/drive/folders/1g32z0LrxjcWYet2n6BFNYuzDsRvmNfdm

22/ A powerpoint version can be downloaded from this folder from @chiawang (it is the file that ends in "pptx"): https://drive.google.com/drive/folders/1g32z0LrxjcWYet2n6BFNYuzDsRvmNfdm

21/ And for people more inclined to learn about the details, check out the literature references etc., this thread explains the @ScienceMagazine paper in more detail:Quote Tweet

20/ If you want to download all the comic images at once, they are available in this folder: https://drive.google.com/drive/u/0/folders/1Qz69bmqQ7qhrMYcWBuPsfsmFlMmASVfz

19/ There are many requests to translate to other languages. So far they are only in English, but I am inquiring if we can make the editable files available, will post here if so.

18/ More information: - Our scientists'FAQs: http://bit.ly/FAQ-A - @ScienceMagazine review: https://science.org/doi/10.1126/science.abd9149… - @TheLancet paper: https://thelancet.com/article/S0140-6736(21)00869-2/fulltext… - @ScienceMagazine paradigm shift paper: https://science.org/doi/full/10.1126/science.abg2025… - Transmission estimator:

17/ How to stop airborne transmission? - Keep distance (helps but not enough by itself) - Ventilation, filtration (+UV in some cases) - Masks w/ attention to fit to the face - Avoid indoor crowding

16/ Plexiglas barriers may trap higher concentrations of aerosols! (and INCREASE, rather than decrease, transmission of the virus)

15/ Surface disinfection CANNOT block airborne transmission (and is a waste of time and money):

14/ Why did so many people get infected despite mask wearing? (not wearing it tight to the face, or low quality filter)

13/ Crowding indoors is a key element for superspreading events

12/ ACE2 is the cell entry receptor that binds and guides SARS-CoV-2 to invade cells

11/ Virus-laden aerosols can enter and deposit in the bronchiolar and alveolar regions of the lungs (also in the nose and upper respiratory tract):

10/ Solar radiation and artificial UV light disable aerosols by damaging their genetic material. (But ventilation and/or filters are preferable to artificial UV whenever possible)

9/ Filters work well to remove infectious aerosols from the air (commercial HEPA or cheaper fan + filter like Corsi-Rosenthal box):

8/ Racing with time: how long do infectious viruses survive in aerosols?

7/ Virus-containing aerosols are impacted by airflow and ventilation

6/ How long can virus-containing aerosols linger in the air?

5/ What is the main difference between aerosols and droplets?

4/ How can aerosols infect through airborne transmission? (by inhalation)

3/ So what are aerosols?

2/ The cast of characters: aerosols & droplets

1/ AIRBORNE TRANSMISSION OF RESPIRATORY VIRUSES: THE COMIC VERSION Supplementary multimedia prepared by lead author @ChiaWang8 to our recent @ScienceMagazine peer-reviewed paper https://science.org/doi/10.1126/science.abd9149… @kprather88 @linseymarr @zeynep @Lakdawala_Lab @zeynep

NEW Viewpoint by @Erik_Klok_MD, @MPaiMD, Menno Huisman & @ProfMakris discussing the epidemiology, pathophysiology, and optimal diagnostic and therapeutic management of vaccine-induced immune thrombotic thrombocytopenia #VITT #COVID19Vaccine https://thelancet.com/journals/lanhae/article/PIIS2352-3026(21)00306-9/fulltext

As of 12.11.2021, we have indexed 257,633 publications: *18,674 pre-prints *238,959 peer-reviewed publications Pre-prints: BioRxiv, MedRxiv Peer-reviewed: PubMed, EMBASE, PsycINFO

Proportion of AY.4.2 (now on http://covid19.sanger.ac.uk) has been steadily increasing in England, which is a pattern that is quite different from other AY lineages. Several of them rose when there was still Alpha to displace, but none has had a consistent advantage vs other Delta.

Are you a Mask Master? Take this quick quiz to find out https://bit.ly/3jbn5iS Wearing a well-fitted mask, along with practicing other prevention measures, is an important part of slowing the spread of #COVID19 High quiz scores = Mask Master badge

Good @NatGeo article by @Ecquis on the growing AY.4.2 variant in the UK with lots of great experts explaining it. And a little bit of me too! At its current growth rate, it will probably become dominant in UK by the end of the year.

Um, @instagram you got this one wrong! @cochranecollab and @CochraneLibrary continue to be there for those looking to use high-quality information to make #health decisions. Learn more: https://buff.ly/2R3c82O And search our evidence: https://buff.ly/2vbkhIJ #infodemic

Research letter reports fertility rates and birth outcomes after ChAdOx1 nCoV-19 vaccination: fertility unaffected; no increased risk of miscarriage and no instances of stillbirth in women vaccinated before pregnancy in global clinical trials. https://hubs.li/H0-N6Hq0

NEW: Today, I released a Community Toolkit for Addressing Health Misinformation. As Surgeon General, I’ve seen how health misinformation sows confusion and mistrust, harms people’s health, and undermines public health efforts.

Learning losses due to Covid were (unsurprisingly) far greater in children from more deprived backgrounds.

Look at this quite shameful graph (from Bob Hawkins) on Covid catch up spending per pupil. All four UK nations provide a few hundred pounds per pupil while others provide thousands. But to make things still worse...

We continue to hear excuses about why low-income countries have only received 0.4% of #COVID19 vaccines: 1. They can’t absorb vaccines. That’s not true. With the exception of a few fragile, conflict-affected and vulnerable countries, most low-income countries are ready to go.

I simply can't get over this graph @FT

Ah yes, "randomization" From an RCT of vitamin D that was recently preprinted

More than 50 #COVID19 cases in Parliament. U.K. still highest infection, hospitalisation & death rates in Western Europe. Still virtually no mask discipline among Tory MPs. Dwindling on public transport too. #Covid19UK

98% of those eligible, aged 12 and older, are fully vaccinated A remarkable public health achievement

Join us for the Scope and Scale of Online Intimidation: How social media is a tool for both supporting and disrupting the circulation of credible info and analysis. With @CaulfieldTim, @whkchun @gruzd @JuliaMWrightDal Register here: https://events.myconferencesuite.com/RSC_COEE2021/reg/landing

I don't have any positives to end on. Today I just want to mark the mega-failure to protect England's children. "Me paenitet, filii mei", as our PM might (should) say.

We're now recognising that the UK's early response to the pandemic was the worst public health failure ever. But it's largely the same people in charge, and they haven't finished failing.

But what's the point? We seem to be a nation bent on self-harm. We kill off our old people, and practically force our young people to be infected with a disease that we still don't fully understand, and which seems to have long-term consequences for a disturbing number.

Nor does there seem to be much point in noting yet again how readily we could've done things differently, and still could, and how this would allow us to greatly reduce Covid transmission in the same way that other nations have done.

I don't really see the point of reiterating why it's a bad idea to allow so many children to be infected -- I don't expect to change anyone's mind at this point.

And the numbers don't show any sign of slowing down. There was a brief dip after the initial meteoric rise in September, but cases are rising again now, and the rolling rate for 10-14s today is higher than it has ever been.

All the same, a million cases is a lot of children. Over a third of these cases have been reported since the start of September this year (i.e., the last month and a bit).

And the figure doesn't include all children (15-17 year olds are in the same age band as 18 and 19 year olds, so it's hard to cleanly separate children and young adults).

This number underestimates the number of infections, of course, because a) there wasn't really any testing of children in the first wave (the graph shouldn't be flat prior to Oct 2020), and b) many children (especially younger children) are asymptomatic when infected.

Today marks a milestone of sorts: the number of children under 14 who've tested positive for Covid in England just passed one million (1,003,787 to be precise).

Some more graphs of us vs our European neighbours. Spot the odd one out.

UPDATE: The @SciBeh and @jitsuvax team has created a new page "COVID-19 Vaccines and Pregnancy". Learn more about the risk of the disease, the safety of vaccination, breast-feeding and common myths about fertility https://c19vax.scibeh.org/pages/pregnancy

Covid-19 has claimed the lives of over 750,000 Americans. That's more than the populations of Alaska, Vermont, Washington DC, or Wyoming. Please, let's not become numb to this tremendous and tragic loss.

Mass infection of kids with a virus less than 2 years old is not ethical, not moral, not scientifically evidenced, not socially just & medically risky. There’s no good argument for this. And no, boosting population immunity to protect the adults is not a valid argument. #Childism

New research Article @TheLancet: Estimating the early impact of the US #COVID19 vaccination programme on COVID-19 cases, emergency department visits, hospital admissions, and deaths among adults aged 65 years and older https://thelancet.com/journals/lancet/article/PIIS0140-6736(21)02226-1/fulltext… #VaccinesWork

WHO has granted emergency use listing (EUL) to #COVAXIN® (developed by Bharat Biotech), adding to a growing portfolio of vaccines validated by WHO for the prevention of #COVID19.

Conspiracy theorists during the pandemic have exploited the provisional nature of scientific consensus and the realities of how science is conducted to paint scientists and health leaders as malign actors, according to a @NatureHumBehav Comment article. https://go.nature.com/3q1JB1I

Well worth reading the full statement, which is available here: https://moh.gov.sg/news-highlights/details/ministerial-statement-by-dr-janil-puthucheary-senior-minister-of-state-ministry-of-health-on-update-on-icu-and-hospital-capacity-1-november-2021

"I would strongly prefer if we can avoid that dreadful scenario. We need to continue to manage the overall number of cases in our population, even as we continue to increase our hospital capacity."

"[M]ore and more cases will translate into more and more ICU beds used, and beyond a certain point that will force us to accept a lower standard of care, and hence have more deaths that could have been prevented."

"What we are trying to do has not yet been done by any other country. We are trying to get to the point where the combination of high vaccination rates, booster jabs & even more boosting from mild infections means that COVID-19 will no longer spread as an epidemic in Singapore."

"We have got to this point in our fight against COVID-19 without excess mortality. We have managed to continue to provide excellent healthcare for all COVID-19 and non-COVID-19 patients. … And we should place a high value on maintaining this standard."

Singapore's Senior Minister of State for Health, Dr Janil Puthucheary, told Parliament on 1 November: "I hope my explanation has helped members understand why although we say we are living with COVID-19, we cannot just open up, and risk having the number of cases shoot up."

this is disturbing: https://twitter.com/dgurdasani1/status/1454383106555842563?s=20… 4/7

depending on interpretation, and interpretation of current UK Covid policy, Singapore is not "the first country" to be trying this 7/7

it's lizard-people-level crazy to think the JCVI meant this: https://twitter.com/BallouxFrancois/status/1454980187976871941?s=20… 6/7Quote Tweet

this is a reasonable thing to consider: https://twitter.com/apsmunro/status/1454792162000916481?s=20… 5/7Quote Tweet

it can't possibly be what the JCVI meant with the respective bullet points in their minutes. Here a selection of that debate: 3/7

The JCVI seems to have at least considered the value of childhood infections as providing boosters for adults, sparking intense debate about the ethics of this, whether this makes epidemiological sense, or whether, in fact, it would be so crazy and nonsensical that ...2/7

interestingly the Singapore Health Minister also mentions "boosting through mild infections" - a concept that is currently generating much furore in the UK in the wake of the release of the JCVI minutes on child vaxx decisions 1/n

1. social norms and content promotion that reward carefully worded material. 2. calling out (and sanction?) of misrepresentation 3. onsite training/support to help people appreciate the kinds of linguistic distinctions that matter to science 5/7

I would encourage people to look over the last 48 hours of the JCVI debate as a 'case study' for the micro dynamics of how things go wrong and to spark ideas for building the information environment we need 7/7

4. algorithms for content aggregation and visualisation that help link connected pieces across the unfolding debate -both to promote accuracy and undercut bad faith "flooding the zone" other suggestions? 6/7

it's not new, but it's depressing every time, and when the stakes are so high, we really need something better. So how can we build a platform that avoids this? Some suggested ingredients: 4/7

in no time, everyone is outraged, and discussion has degenerated to exchanges about "the other side", and away from the actual issues themselves that we should be debating. 3/71

important nuance is lost through repeated transmission of messages via actors who do not understand the subtlety in the language and actors who intentionally ignore/distort it 2/7

the current JCVI minutes debate clearly illustrates the problems with Twitter and scientific debate: meaning glossed, hedges and distinctions left behind, claims about arguments conflated with claims about people, paving the way to ramped up, emotive soundbites and claims. 1/7

Growth advantage and extrapolation of AY.4.2 based on Sanger Institute data in the UK (multilevel multinomial model). Based on this data AY.4.2 seems to have a ~20% growth advantage/week over AY.4 and will become dominant in the UK in December.

Many thanks @FWhitfield for hosting me this Saturday AM @CNN In case it's helpful, I've prepared an informal "fact sheet" on COVID in children and COVID vaccines in 5-11 age group. Highlights attached...feel free to RT or repurpose the information

Life went on except for those who died.

A very disturbing read on the recent JCVI minutes released. They seem to consider immunity through infection in children advantageous, discussing children as live 'booster' vaccines for adults. I would expect this from anti-vaxx groups, not a scientific committee. twitter.com/karamballes/st…

Some of the UK JCVI deliberations are deeply disturbing, eg arguing against childhood vax so that they can get infected & boost immunity in adults. Also imply that vax doesn’t have an individual benefit! How much of this warped thinking is present in Australia? #COVID19Aus

The JCVI has finally released some of its minutes. Shockingly (but perhaps unsurprisingly) they show wildly contradictory positions and opinions based on poor and discredited science. They make for alarming reading. https://m.box.com/shared_item/https%3A%2F%2Fapp.box.com%2Fs%2Fiddfb4ppwkmtjusir2tc

“Circulation of COVID-19 in childhood could therefore periodically boost immunity in adults through exposure” When I say childhood vax ALSO benefits adults, folx say “you can’t use benefits to adults in your argument!” JCVI uses benefits to adults of letting kids get infected

So now we know JCVI considered deliberate infection of children to be helpful for adults. Just appalling. And I suppose now we know why they’ve been so keen to drop all protective measures in schools, and even stop testing in primary schools. They WANTED our children infected twitter.com/Dr2NisreenAlwa…

does there maybe need to be more distinction between points raised for discussion and any actual decision? without knowing about votes etc., it's maybe a bit strong to say "JCVI wanted x..."? I've sat on many bodies with minutes documenting positions I disagreed with

as the fallout from the JCVI minutes build, it's worth considering that the corresponding U.S. body ACIP has been live streaming its meetings on YouTube... transparency helps reduce faulty reasoning...we should have learned that lesson with the very first lockdown, no?

From the paper - ventilation makes a big difference further away, but below 1-1.5m then you'd have to be in a gale to be safe! DISTANCE if you can VENTILATE - works even within 2m, but sadly not so much within 1-1.5m PPE if you have to get close #COVIDisAirborne

"history holds a long record of scientists who were right about one thing and utterly wrong about another, the most extreme example being Nobel disease” https://mcgill.ca/oss/article/covid-19/ivermectin-train-cannot-stop… via @CaulfieldTim

The article is on ivermectin but the sunk intellectual cost fallacy has lessons for us all: "Publicly backtracking when the results refute your idea requires a very large dose of humility” Such humility has been notably lacking among Nobels and other COVID inexperts

2/2 .. with break out sessions in which we will, collectively, be producing a manifesto on this theme!

Please join us at our upcoming workshop on "Science Communication as Collective Intelligence" featuring talks (@SpiekermannKai, @dgurdasani1), panel discussions (@kakape,@CaulfieldTim, @joshua_a_becker, @suneman, @GeoffreySupran and more!) 1/2

JCVI facing calls from within for greater transparency over decision-making https://buff.ly/3GwVqCZ JCVI has been criticised for failing to publish detailed minutes, modelling and analysis behind its decision to advise vaccinating all over-16s in Britain #covid19 #coronavirus

There is nothing new about this idea at all In fact, this is one of the reasons we don’t vaccinate children against chicken pox in the UK It is a totally reasonable thing to include as a point of discussion https://nhs.uk/conditions/vaccinations/chickenpox-vaccine-questions-answers/… 2/

It must be so frustrating to work on an expert committee and have non-experts totally misunderstand and misrepresent your work for their agenda The comment in the JCVI minutes about circulating virus in children providing immunity boosting to adults is a great example 1/

isn't that part of the concern? listing as potential negatives against vaccination population level benefits such as "boosting" adults is not that, right?

2/2 from the paper "We speculate that the extraordinarily high antibody titers observed in vaccinated individuals who develop breakthrough infections may lead to subsequent long-term protection in those individuals."

This study is relevant to the current debate about whether UK's JCVI should have (and actually did) considered the value of children providing a source of booster through breakthrough infections to adults - (in addition to being an interesting study in its own right..) 1/2

No- the statement explicitly talks about infection in children being a 'booster' to adults i.e. children infecting adults to protect them against... infection! I don't think there's any level of cognitive gymnastics that could justify this or make sense of it.

I must confess I do not understand these arguments. Testing would not cause anxiety if it weren't discovering *lots of cases*

John Roberts@john_actuary·Oct 27So strong evidence here to support the need for booster jabs, and maybe to suggest that 6 months is slightly too late to prevent many serious infections of the retired population in the run up to Xmas. Report here: 7/7

To reiterate the point, most 60-64 year olds were double vaccinated in May, around 5 months ago. The low point was a couple of weeks after that, but the percentage not showing antibodies has risen from under 5% to 12% in just three months. (CI for that last pt 84% to 91%). 6/

At this point I'll caveat, as does ONS, that simply not testing positive for antibodies doesn't mean that there is no immunity. But nevertheless, the data is consistent with others that show a waning of immunity after around five months, based on hospital admissions. 5/

...if you look at the last 5 months, you can see that the proportion has roughly doubled, from 6% to 12%. (That's 5 months, not 6, by the way, which is the current threshold for boosters). 4/

Concentrating on the oldest three age-bands, let's now flip it around, and look at the percentage not testing positive, which may be a proxy for any effectiveness gap. In this view, it still looks OK, in comparison to pre-jab levels, as you might expect. But wait... 3/

First here's the picture for all the age groups. Note how for some of the older lives the olive green line is starting to dip down, as the proportion testing positive for antibodies is falling. It's noticeable from 60 upwards. 2/

After a month's absence, the ONS antibody study is back, and shows that levels measured are still in excess of 90% across the UK (highlighted in yellow below). I'm going to focus on the older lives though. 1/

No age graphs today. I spent the morning trying to approximate an adjustment for deaths since the second jab. However, today, the NHS has moved the age bands on from 31/3 to 31/8, so I now need to spend some more time considering the impact of that on my charts. 3/3

The run rate of 1.6m continues to be well short of those becoming eligible, so the backlog grows. After a brief dip below 2m, the required number will be around 2.1m/2.2m for the next month. 2/

Thu booster (& 3rd primary) update. 237k today, up an unimpressive 6% on a week ago. Total now 5.9m, out of 11.7m double jabbed six months ago. The "backlog" is now also 5.9m. Some of the backlog will have appts booked in, and sadly around 0.25m will have died. 1/

When does the suffering become too great? Well, that's up to us. We all have our own limits of other people's suffering that we're willing to tolerate. But the people who would see it - doctors, nurses, care workers, patients, will all tell you that it is unacceptable now. 7/n

What happens now in the reasonable worst case scenario? This. More of this. That's all. It won't be like a disaster movie. We'll just see more people suffering more, and dying a little more often, in preventable ways. 6/n

So mistakes happen. More little mistakes, more big mistakes. Everything gets just a bit riskier with each new patient who arrives. Don't take my word for it, we have robust evidence. https://link.springer.com/article/10.1007/s00134-018-5148-2#change-history… 5/n

That means that you have to wait longer for everything, you get cared for by more exhausted, less experienced people with less support, tests and investigations are delayed, and you may be cared for in a part of the hospital that doesn't normally deal with your problem. 4/n

The main problem is Covid: more Covid means fewer nurses and doctors (they get it too), and more patients. We have too many patients, and not enough staff. 3/n

When a healthcare system fails, increasing numbers of people suffer and die needlessly. That's all. If you aren't a patient or staff, you don't see it. But this is happening, now, all over the UK. 2/n

I've been thinking about this and the responses. There are many complex problems in the NHS but I can give you some simple, important facts that I know to be true, from my own observations. 1/n

Updated data from Israel. The booster works, without any doubt! Red (empty battery): un-vax Light green (half battery): 2nd dose without the booster Green (full battery): with the booster

Thanks @MKushel and others for helping bring their voices front and center in the conversation. Highly recommend this piece. (3/3) cc: @KellyMDoran @JessieGaeta @vineet_chopra @gregggonsalves

This during a time when so many people have turned their backs on this vulnerable population (Or are actively trying to destroy their lives @Kim_Janey and @bostonpolice). We have a CIVIC RESPONSIBILITY to help ppl experiencing homelessness. (2/3)

A study in @JournalGIM by @MKushel found "the majority of participants [who experienced #homelessness] expressed a positive inclination toward vaccine acceptability, citing...CIVIC RESPONSIBILITY." (1/3)

Year-to-year change in age-adjusted death rate in the US from 1960-2020:

WFH really is only for a very privileged few now. Not sure how that can stay a “thing” as an NPI. Too many harms being done by a fractured society where people are thriving by getting other people to bring them stuff/ make them things/ look after their family members for them

Thankfully, we have not seen any evidence of antibody-dependent enhancement of infection or disease by any COVID vaccines to date. Vaccine are not making infections worse, and are very effective in preventing disease.

Diese Grafik vergleicht die Inzidenz und die Impfquote in den Bezirken.

Twitter’s own research shows that it’s a megaphone for the right. But it’s complicated.

ONS data published today: 1.8% of the England population had covid during the weeking ending 16 Oct. That is 1 in 55 people. The highest rate in secondary school kids. That is 7.8% of them. That is 1 in 12.

It'd be nice if boosters could speed up a little more. Earliest data (1st October) showed a backlog of 3.1m doses (eligible minus given). Now it's 4.1m.

The 80+ percentage is rising rapidly, up 5% (from 18.3%) in the 3 days since I started reporting these figures. Note many boosters are also being given to H&C workers, which is presumable why the figures below 65 are slightly higher than immediately above it. 2/2

154k booster reported today in , bringing the total to 1.58m, out of 4.56m. So that's another 3m eligible for a jab as soon as they can be scheduled in. 1/

So, in the end, 0.3% of employees didn't comply with the company's vaccine mandate.

When asked on @CBSMornings about the company's vaccine mandate for staff, the CEO of @united airlines also said, "Out of our 67,000 U.S. employees, there are 232 who haven't been vaccinated. They are going through the termination process."

Wales is first with their vaccine stock data this week, with a solid 1.6m new doses made available to the UK roll-out programmes. Again, the comically slow progress of the teen and 50+ roll-out is not down to supply.

The next fortnight could get pretty damn ugly. Here's hoping the we are near the peak

Exponential

note that some of these mean *more* missed school/learning loss; eg schools that dont mask are probably more likely to keep some kids at home or close

some of the things to compare to learning loss / missed school when considering risks/benefits of masking and other NPIs re schools:Quote TweetSeth Trueger@MDaware · 13 Augvs the risks of kids getting sick and dying, kids being around kids & family members who get sick and die, missing school due to more quarantines and closures, the pandemic dragging out longer & longer if mitigation efforts are not usedShow this thread

Quote TweetShay Stewart Bouley@blackgirlinmain · 13 SepToday's kids are living through something that not even the adults have lived through. A global pandemic with 4 million people dead and counting. Why do we expect them or ourselves to get back to normal? We are trying to prepare them for a world that may no longer exist.Show this thread

This work was led by @AthenaAkrami and Hannah Davis. Please do follow her, and the many groups who have educated us about this through their lived experience including @LongCovidKids

Also, want to add that there's amazing patient-led work in this area which looked at 74 symptoms of long COVID, and consistent with many other studies showed that neuro-cognitive symptoms tend to increase and persist over time, which is deeply concerning.

Sorry, earlier tweet should have read 'but it doesn't affect *young* people', Yes it does!

I partly wrote this thread so anyone could use it to counter false narratives & unevidenced critique from long COVID deniers. Please feel free to link it to anyone who suggests there isn't strong evidence for long COVID. They can then engage on facts.

And pl follow @Daltmann10 @VirusesImmunity @kamleshkhunti @Dr2NisreenAlwan @trishgreenhalgh for accurate information on this.

If you are one of the scientists who made this choice, please be honest that this is ideology, and not science. Because the evidence tells us to be very very cautious about exposing children to infection, & that the benefits of vaccines far outweigh harms.

Choosing to expose children to infection rather than vaccinate them, when millions across the world have been safely vaccinated is negligent, and harmful. We are exposing children to a multi-system chronic illness we don't understand & don't know how to treat.

There is scientific consensus that this is not just a respiratory disease, but a multi-system one. Here's really good review from Nature medicine on this. So let's not follow ideology. Let's follow the current evidence. All of which is gravely concerning.

So there is uncertainty- but this uncertainty doesn't mean we can ignore these very real risks - when all signs are pointing in a very worrying direction. We *must* adopt the precautionary principle & protect our young from this multi-system chronic disease.

yes, we don't fully understand the underlying pathology yet, and this will take time, but all indications are that it is serious - even in children. And very likely affects multiple organ systems, with long-term impacts even on young people.

I hope this will go a way to convince those who still aren't that long COVID is a biologically complex syndrome, that is common, and concerning. It impacts young people, and is often quite functionally severe and debilitating. So let's not minimise this.

There are also many studies that suggest SARS-CoV-2 impacts our immune system- including T cell ageing & dysregulation of immune responses following infection. There is also evidence of virus persistence in some tissues. I'm not an immunologist- pl follow @fitterhappierAJ on this

Organ disfunction was common, and far more prevalent in those hospitalised with COVID-19 than in the control group. And more associated with COVID-19 in under 70s compared to over 70s.

Another large study among those hospitalised in England showed that 1 in 3 were re-admitted after discharge, and 1 in 10 died within 5-6 months. This was 4-8 times higher than in the control hospitalised group studied - matched on many factors.

The risk of organ dysfunction was 38·9% in those aged 19–49 years - clearly impacting a very high proportion of young people as well.

We also know that acute infection has impact on many organ systems in those affected with severe infection, including among young people. A recent study of >70,000 hospitalised patients showed that *half* had at least one organ system affected- lung/kidney/heart/brain/gut

What else do we know about what COVID-19 does to our immune system? There's good evidence now that acute infection with COVID-19 leads to a plethora of auto-antibodies against many tissues in our body. We don't know the impact of these fully yet.

Neuro-psychiatric disease is common post-COVID even among those not hospitalised with severe infection. COVID-19 also appears to be associated with increased risk of strokes, and other neurological conditions at 6 months post infection:

I've summarised some of the evidence here. There is strong evidence now that even those with mild infection can have long-term structural brain changes, including thinning of grey matter is specific brain areas related to smell, taste, memory & emotion

The cognitive symptoms (brain fog, memory loss, difficulty concentrating, sleep disturbances) tend to become prominent later in long COVID, & also last longer. These are worrying also because there are now studies showing the virus affects the brain, even in younger people.

Another study from Norway showed persistent symptoms at six months were even more common, where over half had persistent symptoms at 6 months (including children). These were people self-isolating at home so not severe illness needing hospitalisation. https://nature.com/articles/s41591-021-01433-3

Risk factors that increased risk included being a woman, increasing age, smoking, and low income, deprivation, and severe acute infection requiring hospitalisation. That this is a disease that affects disadvantaged & women more might explain why many are happy to dismiss it.

So if symptoms persist for 12 weeks as they do in 1 in 3 people as per the REACT-1 study, they tend to persist for much longer (up to 22 weeks or more). Also 1/3rd of those with one symptom persisting said it impacted their day to day lives- that's just above 10% of cases.

For most affected, this wasn't a single symptom. It was a combination of many symptoms. e.g. 20% of those infected reported 3 or more symptoms and 17% reported 4 or more symptoms at 12 weeks. Note that there isn't much drop off in prevalence of symptoms after 12 wks

So what does the REACT-1 study, which examined more than half a million people show? This study is limited to >=18 yr olds in England. This examined 29 symptoms, and showed 1 in 3 people with COVID-19 had symptoms lasting more than 12 weeks. This included young adults.

These 400,000 sadly include 9000 children who have been affected for more than a year. This isn't a mild syndrome, or a short one for thousands of our young- who've been impacted due to policies where they were forced to go into unsafe environments without adequate mitigation.

This means the ONS estimate may be underestimating the prevalence of long COVID considerably. Also these symptoms are not mild. Of the ~1 million people affected, 2/3rds said it impacted their day to day activity. And 400,000 have had persistent symptoms for more than a year.

'But it's just mild symptoms that don't matter, and most people only have 1 symptom' Unfortunately, there's a plethora of symptoms, and many of them are very common, so many people present with a combination of symptoms. The ONS only examined 21- there are 100s of symptoms.

'But it doesn't affect old people'... it absolutely does! The majority of those affected are <50 yrs. And it affects children. Between 10-13% of children have symptoms for 5 wks or more, and 7-8% of children had symptoms for *12 wks or more* compared with <2% of controls.

This strongly challenges the rhetoric by some about 'floating numerators' & that this is 'background symptoms' in the population. The ONS survey showed very clearly that 13.7% of those infected (1 in 8) developed long-term symptoms > 12 wks compared to <2% controls

The ONS data compares symptoms post-infection among those infected with control groups of those confirmed not to have infection. Persisting symptoms were *8x* more common among those testing positive with PCRs compared to those who were negative.

First, ONS data & REACT-1 data- these are some of the most robust data on long COVID. Why? -They include infections based on PCR tests through random nationally representative surveys of thousands of people -ONS data was based on 313,216 samples, REACT-1 on 508,707 people

Some stats first - there are several studies that now put the overall incidence of long COVID as between 10-50% of those infected, depending on symptoms studied & cohorts studied. Let's look at some of these.

Ok, time to do a thread on long COVID. Long COVID is a *real* multi-system syndrome that occurs in those infected (far more common than in uninfected controls)- predominantly impacting the young. Let's do a deep delve into this syndrome that some in JCVI are in denial about!

In sum, RCTs of masks were difficult to do, and participants randomised to wearing masks didn’t comply well. But these RCTs were in the context of – for example – a flu outbreak on a university campus in a country that had never seen a deadly pandemic of anything. 31/

There haven’t been many RCTs of masks in the lay public. It’s easier to randomise healthcare workers. A few (pre-Covid) RCTs in semi-institutionalised settings (university halls of residence) are summarised here. https://onlinelibrary.wiley.com/doi/full/10.1111/jep.13415… 30/

Note: as a long-term survivor of a poor-prognosis cancer, I owe my life to RCTs of drugs and surgery. RCTs are fantastic for testing both treatments and vaccines, and have led to many lives being saved in the pandemic. But they are problematic for testing masks. 29/

In short, EBM’s preferred methods are unsuited to studying some aspects of the pandemic (notably masks), as is its philosophy of demanding definitive findings and waiting until you’ve got them. https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1003266… 28/

These two issues—the near-impossibility of using RCTs to test hypotheses about source control and over-reliance on “statistically significant effects” within a short-term intervention period—is why a RCT of masks is *highly likely to mislead us*. 27/

=> if masks reduce transmission by a TINY bit (too tiny to be statistically significant in a short RCT), population benefits are still HUGE. UK Covid-19 rates are doubling every 9 days. If they increased by 1.9 every 9 days, after 180 days cases would be down by 60%. 26/

Take the number 1 and double it, and keep going. 1 becomes 2, then 4, etc. After 10 doubles, you get 512. After 10 more doubles, you get 262144. Now instead of doubling, multiply by 1.9 instead of 2 (a tiny reduction in growth rate). After 20 cycles, the total is only 104127. 25/

More fundamentally, we’re not just interested in whether my mask protects either me or you from catching Covid during a short intervention period (say, one month). We’re interested in how masking impacts on the *exponential spread* of an accelerating pandemic. 24/

The RCT design can’t cope with this. It’s easy to design a study where the primary outcome is infection in wearers, but how would a RCT of source control work? I consent to wearing a mask, but the whole town must consent to be tested (at baseline & repeatedly) for infection. 23/

Many reasons. Drugs are (arguably) a simple intervention, but masks are a highly complex one. As we all know, there are two key questions: do they protect the wearer from other people’s germs – and do they protect other people from the wearer’s germs (‘source control’)? 22/

Random allocation means that differences between the arms of a RCT are highly likely to be due to the intervention (in this case, masks) and not to confounders. But it does *not* follow that a RCT is better, for any scientific question, than a non-RCT design. Why not? 21/

A RCT is a controlled experiment. Since people (or animals) are randomly allocated to one or another group (‘arm’), any confounding variables are distributed evenly between the arms so they all cancel out (so long as the study is large enough and allocation is truly random). 20/

If you were raised in the EBM tradition, where “rigorous RCTs” are mother’s milk, it’s not easy to get your head round why this was a bad way to approach the problem. Looks like Prof Greenhalgh has lost it, dropped her standards, joined the dark side etc. Bear with me. 19/

In the name of evidence-based medicine (EBM), the West got off on the wrong foot. We became obsessed with the holy grail of a definitive randomised controlled trial (RCT) that would quantify both the benefits and the harms of masks, just as you would for a drug. 18/

There was never one jot of evidence for risk compensation. But as Eleni Mantzari and team showed, scientists *talking up* risk compensation as a purely hypothetical problem led to significant negativity towards masks. https://bmj.com/content/370/bmj.m2913… 17/

The other masks-are-harmful meme related to risk compensation. If you wear a mask, you’ll feel protected and take more risks. Like the driver who becomes more reckless when wearing a seatbelt, you’ll be slapdash about hand-washing and you’ll get too close to passers-by. 16/

There was an alternative, common-sense view. Your cotton mask is no more likely to kill you than your cotton T-shirt which you pull over your head. In mid-2020, @jeremyphoward came up with the slogan “it’s a bit of cloth, not a land mine”. 15/

The meme that *touching your own mask* could kill you was an extraordinary fantasy in which many reputable scientists got swept up. Masking was depicted as a highly specialist activity, dependent on perfect donning/doffing procedures. The public simply weren’t up to it. 14/

This never made sense. If your mask contains virus, it’s likely come from you, so you’re already infected. There was never any evidence that people touch their faces more when masked. They touch them less. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2768767… 13/

The putative harms of masks were twofold. First, self-infection. The idea was that the mask was dirty, and by touching it (while putting it on, or when your face itched under it) you might transfer virus to your hands and thence to your eyes etc. 12/

The most fundamental error made in the West was to frame the debate around the wrong question (“do we have definitive evidence that masks work?”). We should have been debating “what should we do in a rapidly-escalating pandemic, given the empirical uncertainty?”. 11/