How often does a face mask stop a virus?

[Goonshow]

I'm curious about this. It now appears to be widely accepted that a face mask helps stop a virus spreading. But how often does a single mask do the job and save a single infection?

I think it happens rarely. I don't think masks stop the virus much, if at all, and I find the blind acceptance that they do puzzling.

My initial guess is that a mask worn by someone each day will stop transmission of the virus less than once a year.

Anyone else care to give their thoughts?

It appears to have been accepted by the majority that masks stop the virus. My feeling is that they don't, but my next question is how many times do they stop the virus?

OP, if the person sitting next to you on the bus has COVID, wouldn't you prefer they were wearing a mask? Or are perfectly OK with no protection at all? Because that's your premise here.

[quote McSilkson]Round-up of the still extremely poor evidence for effectiveness: swprs.org/face-masks-evidence/[/quote]
Are you a member of swprs yourself?

(For those unaware of what swprs is, it's a tinfoil hat group of conspiracy theorist pseudo-academics)

I'm skeptical. Especiallyas I have been told by an NHS infection prevention and control team that most outbreaks come from touching a surface that has the virus on it. If you then add a mask into the equation which people touch all the time, you are touching your face more when wearing a mask than not wearing a mask. So the chances of you giving yourself the virus by accident must be higher.
I'd love to know if there have been any studies in subconscious face touching when wearing V not wearing a mask. But we do need to have a visible reminder of the viruses presence, if the gov just told us to wash our hands and everything will be ok the masses would see this as a disproportionate reaction and demand more action to be taken. Hence face masks.

@chocolateorangeinhaler

I'm skeptical. Especiallyas I have been told by an NHS infection prevention and control team that most outbreaks come from touching a surface that has the virus on it. If you then add a mask into the equation which people touch all the time, you are touching your face more when wearing a mask than not wearing a mask. So the chances of you giving yourself the virus by accident must be higher. I'd love to know if there have been any studies in subconscious face touching when wearing V not wearing a mask. But we do need to have a visible reminder of the viruses presence, if the gov just told us to wash our hands and everything will be ok the masses would see this as a disproportionate reaction and demand more action to be taken. Hence face masks.

Yes, that's obvious. A mask has to be used correctly to be efficient.

I don't know if there needs to be a study to prove common sense tbf.

Masks also need to be proper ones not some "face covering" you've bought from Joules because it matches your handbag. In places where schools are open and have been for a while, and things are definitely looking to be turning a corner, you're only allowed to wear surgical paper ones or the FFP2 type ones.

I remember around April last year when I mentioned in my place of work we could only wear surgical ones, being berated by someone saying they didn't work. That'll be why in my town during the spring we had a total of 31 cases. In 60,000 people. If only we'd known that the masks we had to wear weren't working eh?

This is a really interesting thread OP. Its great to read everyone's thoughts.

While we're at it, could people take a moment to feedback about why the predicted mass of the quantum vacuum has little effect on the expansion of the universe?

No? Didn't think so .

@goonshow I've worn a mask since it has been law at supermarket etc. As neither me nor anyone in my family or close contacts have had it then the mask has never had to do its job. (Following the you wear a mask to protect others theory).
On a day where there were 60000 cases, if all 60000 of those people went to the supermarket the two days before, and wore a mask and came into close contact with 20 people each day, and the mask prevents maybe 25% of potential transmission (although I'm sure I read it was 6% somewhere), then 5 people per person per day have been spared. So that would be 600000 cases prevented over two days by 60000 people wearing masks. Even at 6% this would be 120000 prevented transmissions.
So for me my mask has never done its job, but if you pool all the people with Covid who are actually the only people who can prevent transmission then the mask has done its job when it actually could do its job.
I suppose you could then look at the chain of transmission as those 600000 people who didnt catch it also didn't pass it on and it has a big impact.

I think they're health theatre on the whole. They're cheap(ish) and highly visible. Sadly that means they'll probably be the last to go.

@ShouldHaveCouldHaveWouldHave

OP, a close relative was recently hospitalised with Covid. Had only popped to supermarket once or twice in the weeks beforehand, wore a mask every time. Shows how much use they are.

However, the point of mask wearing is that if everyone in the supermarket had been wearing a mask your relative might not have caught covid.

Masks provide some protection, they absorb/deflect water, viruses are expelled in water droplets so if you breathe out and you are harbouring the disease, much of it will be absorbed by the mask, and anybody you talk to / droplets in the air can be absorbed by the blue side of the mask. The virus particles aren't really wandering around themselves, they're sat in droplets of water or inside sloughed cells from the respiratory tract, which are much bigger and can be absorbed by the masks

Saying that I have never bothered with fabric masks, I use 3 and 5 layer disposable masks and only use once

Well I was hopeful about their effectiveness until I wore a face mask queuing outside a shop on a cold morning and could see my breath and most other peoples in the cold air. Now I double mask in certain busy indoor busy situations. Seems to be better with the outside breath test.

Masks provide a layer of protection. They reduce risk, not eliminate it. If not used properly they are useless at best and increase risk at worst.

Most people don't know how to use them properly. That's the problem.

To me it's bonkers people are so bothered about masks. They're I minor inconvenience if that. Yet have the potential to reduce the spread. So I don't really understand the fuss? Feels like just a thing to whine about.

@ItsLoisSangersFault

This is a really interesting thread OP. Its great to read everyone's thoughts.

While we're at it, could people take a moment to feedback about why the predicted mass of the quantum vacuum has little effect on the expansion of the universe?

No? Didn't think so .

:o

Personally I think if you drew up a list of all the things we can do to prevent/reduce the risk of either getting or spreading covid, masks would be pretty low down that list.

Your model doesn't make sense for me. If 100 people wear a mask, but none of them have Covid for a year (symptomatically or asymptomatically), then no Covid is stopped. Because there wasn't any to stop.
We already understand that wearing mask mainly protects others from your Covid.

Asian countries who dealt with airborne viruses before think they are important. Perhaps look at their research.

Do we think masks helped to reduce flu this year?

@110APiccadilly

I think they're health theatre on the whole. They're cheap(ish) and highly visible. Sadly that means they'll probably be the last to go.

OK - so if it's theatre, if my COVID patient I mentioned upthread taking the bus refuses to wear a mask, and you have to sit next to him, that's fine with you? Your journey is half an hour, there is no ventilation, and he's one of those people who loves a conversation.

@SummerIsComing2019

This must be the most idiotic thread I've ever read on mumsnet and I've been around for 7 years. Sorry, no offense to anyone, I just can't believe what I'm reading

I know! I've read a fair few daft threads on here, particularly during covid times, but this takes the biscuit.

Each COVID measure isn’t foolproof And May only have limited efficacy in reducing transmission. It’s the culminative effect of all measures where it is hoped it will reduce transmission. Handwashing, distance, masks, stay at home etc. I would have thought that was obvious.

@TheClaws Umm... I don't really want to sit next to him with a mask. If I do have to sit next to him, I don't care whether he wears a mask!

@Okokokbear

To me it's bonkers people are so bothered about masks. They're I minor inconvenience if that. Yet have the potential to reduce the spread. So I don't really understand the fuss? Feels like just a thing to whine about.

To the anti-maskers it's an obvious sign of compliance and being a sheeple. Their fragile little egos can't cope with that so they call them face rags and muzzles and start threads like this on mn.

I know! I've read a fair few daft threads on here, particularly during covid times, but this takes the biscuit.

Of course let's assume the variables for biscuit taking are number of biscuit havers, biscuit transmissibility, and biscuit takers. Now, I personally think a biscuit exists once a day, there's no way to prove that though. Let's all post our beliefs on proving crumb trails.

@Goonshow,

Your ‘model’ is not a model in the scientific sense of the word, it is just a crude estimate based on erroneous assumptions.

The variables need to include the prevalence of Covid in the general population, the average number of viral particles needed to induce symptomatic infection, the reduction of particles by the mask etc etc. It is a far-from-trivial calculation and needs decent statistical techniques to be properly modelled.

A team from Cambridge university did this in June last year and came to the following conclusion:

‘ The study suggests that an entire population wearing masks of just 75% effectiveness can bring a very high ‘R’ number of 4.0 (the UK was close to this before lockdown) all the way down to under 1.0, even without aid of lockdowns.’

The study can be found here;

www.cam.ac.uk/research/news/widespread-facemask-use-could-shrink-the-r-number-and-prevent-a-second-covid-19-wave-study

And here is another study from The Lancet suggesting mask wearing supports infection control:

www.thelancet.com/journals/landig/article/PIIS2589-7500(20)30293-4/fulltext

Evidence and peer reviewed study trumps anecdote and unscientific back-of-envelope guesstimates every time.

I love this thread well done to OP for her modelling. Please come back and defend it though, you and your calculator may have stumbled on to something that scientists and epidemiologists around the world have not!

[quote 110APiccadilly]@TheClaws Umm... I don't really want to sit next to him with a mask. If I do have to sit next to him, I don't care whether he wears a mask![/quote]
So ... you read the part where I noted he had Covid, right? So, if you sat next to someone with Covid for half an hour, chatting - both of you maskless - that's fine with you? This sounds ... stupid. Sorry.

I work in retail in a staire with 70 employees

Non of us have had the usual coughs,colds and flu illnesses we usually have .... nobody has been off sick in the past 6 months at all in fact!