The study uses PHE modelling data on infection rates, as case data over the year is unreliable (we tested only people who were admitted to hospital during the first wave)
Through this, they estimate just short of 500,000 infections
This is a massive underestimate
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We can get a better estimate of total infections by measuring seroprevalence - who has positive antibodies
By July last year, 4% of children were positive - that is already nearly 500,000 BEFORE the second wave
Many people believe children are more likely to have false negative results to:
- antibodies tests, due to them having mild illness
- PCR tests, due to difficulty sampling
Turns out, that's almost never the case
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First, antibody tests
Most serology tests used in studies test for antibodies against the Spike protein (we call these S IgG)
This nice Australian study, found no difference in rates of children seroconverting to S IgG compared to adults
Waiting for data before frightening kids, parents and the general public about variants, children and schools is important. They deserve this.
It has not been well practiced across the board - and given todays @ONS data, it is particularly disappointing
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Many will remember (feels like a lifetime ago) a lot of concern about the Alpha variant (prev known as B1.1.7) being very transmissible or more severe in children, disproportionate to its effects in adults
As people much smarter than me have said, the issue of vaccinating children against #COVID19 is a tricky one
I urge caution if you think it is straightforward
A quick look at recent developments and decisions from around the world to put this into context
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A quick recap of main considerations:
-Children's risk from #COVID19 is extremely low
-Vaccines are very safe but do have some rare adverse effects
-Vulnerable people in other countries need vaccinating, and supplies are limited
-Younger children are different from teens
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First to Germany 🇩🇪
Following EMA approval of Pfizer for 12 - 15yo, their vaccine advisory committee is recommending the jab only for those with existing comorbidities putting them at higher risk
There are some claims that the ongoing randomised trial of Daily Contact Testing (DCT) vs blanket quarantine/isolation in schools for cases of #COVID19 is "unethical"
Here is a short thread on why that is completely wrong
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Randomised trials are indicated (ethical) when we have "equipoise", meaning we can't be sure which of some options is better
We want to get the best of all outcomes, e.g. a pill which is really good at treating mild coughs but frequently causes cancer is not good overall
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For COVID-19 cases in schools, we know that we want to avoid transmission, but we also know that children missing school is harmful
There is equipoise as to whether the best of *all outcomes* is blanket quarantining of bubbles, or doing DCT
Some decent data is now emerging regarding prolonged symptoms after acute #COVID19 infection in children
Fortunately the data looks reassuring 👍
Low prevalence of prolonged symptoms in children, especially when compared to a control group
Let's take a look!
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First, a large serology screening study from Switzerland 🇨🇭
No difference between seropositive and negative children with symptoms beyond 4 weeks (~10%), and similarly very low rates of symptoms at 6 months (2 & 4%)