Some people asked me how I got COVID when I wear an FFP3 to teach.
So I thought I'd revisit "The Swiss Cheese Model" to explain. A🧵
As the diagram shows, it involves firing lasers at cheese.
The cheese blocks the beams. The more layers, the fewer lasers get through.
So I thought I'd revisit "The Swiss Cheese Model" to explain. A🧵
As the diagram shows, it involves firing lasers at cheese.
The cheese blocks the beams. The more layers, the fewer lasers get through.
Incidentally, I was taught by Professor James Reason, the originator of the model, when I was an undergraduate.
Many years ago.
If someone is trying to prevent accidents, then a good principle is to use "Lasered Protections".
Many years ago.
If someone is trying to prevent accidents, then a good principle is to use "Lasered Protections".
Of course someone on YouTube has made a video of what happens when you repeatedly fire lasers at cheese.
You can use it to understand UK policy on COVID safety in schools and hospitals.
If I were a scaremonger, I might say "this is your brain after a COVID infection".
I'm not.
You can use it to understand UK policy on COVID safety in schools and hospitals.
If I were a scaremonger, I might say "this is your brain after a COVID infection".
I'm not.
I did once work as a cheesemonger.
Sainsbury's deli - aged 16-19.
I wore a straw hat. It's when I first realised that perhaps the PPE that workplaces provide might not be appropriate.
We have good cheese in the UK.
Sainsbury's deli - aged 16-19.
I wore a straw hat. It's when I first realised that perhaps the PPE that workplaces provide might not be appropriate.
We have good cheese in the UK.
Sorry, "Layered Protections".
Respirator masks are brilliant. I've been teaching in them since 2021 and nothing has got through my mask at school.
My children wear them too.
But that's the only protection they get. We think COVID got around, rather than through their masks.
Respirator masks are brilliant. I've been teaching in them since 2021 and nothing has got through my mask at school.
My children wear them too.
But that's the only protection they get. We think COVID got around, rather than through their masks.
Back to the lasers!
If you pause the video, it's possible to find the exact moment the cheese gets hit with the laser.
But that's not how the Swiss-Cheese-Model-of-Accidents-applied-to-COVID works.
Instead, play the video normally, and hit "screenshot".
If you pause the video, it's possible to find the exact moment the cheese gets hit with the laser.
But that's not how the Swiss-Cheese-Model-of-Accidents-applied-to-COVID works.
Instead, play the video normally, and hit "screenshot".
1st exposure
Sick child in my class.
Ok, didn't get hit by the laser!
The COVID protection used worked to prevent infection.
Great news.
Sick child in my class.
Ok, didn't get hit by the laser!
The COVID protection used worked to prevent infection.
Great news.
2nd exposure
Sick colleague.
Didn't get hit by the laser either!
These masks work really well!
Even when children use them.
Sick colleague.
Didn't get hit by the laser either!
These masks work really well!
Even when children use them.
3rd exposure
Sick child in a colleagues class, but I used the room after them. #CovidIsAirborne and you can catch it from someone who was in the room before you arrived.
The mask worked.
Sick child in a colleagues class, but I used the room after them. #CovidIsAirborne and you can catch it from someone who was in the room before you arrived.
The mask worked.
4th exposure.
This is not meant to be funny. I'm not doing call-backs or anything.
Sick child in my son's class.
His mask worked.
This is not meant to be funny. I'm not doing call-backs or anything.
Sick child in my son's class.
His mask worked.
I'm just doing random screenshots. It took me about a minute to do all of them.
This is some cheese that's been melted by laser.
All the cheeses.
This is some cheese that's been melted by laser.
All the cheeses.
5th exposure.
This was a close call. My son's friend came in with active Covid. My son had the presence of mind to lend him a mask.
2 less-than-perfect masks will stop COVID.
This was a close call. My son's friend came in with active Covid. My son had the presence of mind to lend him a mask.
2 less-than-perfect masks will stop COVID.
6th exposure
Me again. Another sick child in my class.
The mask worked. Again.
Me again. Another sick child in my class.
The mask worked. Again.
7th exposure.
Presymptomatic child in my son's class.
The parents have COVID. They sent the child in anyway.
The mask works.
Presymptomatic child in my son's class.
The parents have COVID. They sent the child in anyway.
The mask works.
If you are starting to see a problem with this model, we aren't done yet.
8th exposure.
My son's school. The child was sick, but "their attendance is already too low" and they are forced into school.
Still, the mask worked.
My son's school. The child was sick, but "their attendance is already too low" and they are forced into school.
Still, the mask worked.
The next week, just due to chance, neither my sons nor I meet anyone with Covid.
Even though we are all in school.
This happens sometimes.
It's a school, not a COVID ward.
We are not constantly exposed.
Even though we are all in school.
This happens sometimes.
It's a school, not a COVID ward.
We are not constantly exposed.
Nth exposure.
Covid gets around, or through the mask.
Children can't control their environment in the same way adults can.
They've been keeping this up every day, for years.
We can't contain it at home and everyone gets sick.
Covid gets around, or through the mask.
Children can't control their environment in the same way adults can.
They've been keeping this up every day, for years.
We can't contain it at home and everyone gets sick.
The problem with schools and hospitals is that COVID policy is as silly as firing laser beams at cheese repeatedly.
There is no attempt to control infection.
In fact, the opposite is true. Infection is encouraged.
There is no attempt to control infection.
In fact, the opposite is true. Infection is encouraged.
No single layer of cheese can cope with so many laser beams.
Obviously we need more cheese.
We should use all the cheeses.
But critically, we need fewer laser beams.
Obviously we need more cheese.
We should use all the cheeses.
But critically, we need fewer laser beams.
The Swiss Cheese Model presumes that we are TRYING to prevent accidents (or COVID).
We are not.
It's all lasers and no cheese.
We are not.
It's all lasers and no cheese.
If there are fewer laser beams, it's possible for a single layer of cheese to keep you safe for a long, long time.
Maybe even for years.
We need to reduce the frequency with which children are exposed to Covid.
Stop firing so many laser beams at cheese.
Maybe even for years.
We need to reduce the frequency with which children are exposed to Covid.
Stop firing so many laser beams at cheese.
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