This is a suggestion for a way to resolve questions such as:
- How effective are the best FFP3 / N99 masks at breaking transmission of COVID?
- However effective is eye protection when combined with the best masks?
- How effective is ventilation with HEPA filters?
Informed expert opinion can't resolve these questions at present with opinions that range from almost no effect to highly effective. We have many studies but most are observational and from the range of expert opinion it is clear that so far they have had limiations and are not conclusive.
China is a country that has the motivation to find answers fast, and has a culture that is very accepting of masks. It also has very high prevalence of COVID during the surge, which should lead to rapid results.
- We need to resolve this with science
- my idea of a randomized controlled trial of masks in households
- interested in comments from experts about whether it would work
This is my own idea of Randomized Controlled Trial of masks in households. I had it some time back and shared it at the time but got little attention. Perhaps with COVID spreading so fast in China its time has come?
This is my tweet summary:
Could High Quality Masks Solve China's COVID Problems?— Robert Walker BSc, fact checker for scared people (@DoomsdayDebunks) December 19, 2022
Idea For A Randomized Control Trial Of Masks In Households To Find Out
[with the rapid spread in China we'd likely get results with fewer households faster] pic.twitter.com/4UBwKLFQPW
The idea is that:
1000 households with a minimum of 4 household members each agree to wear masks habitually at home if asked to do so - NO OTHER CHANGES in their mask wearing outside of their homes, just wear masks or not as they would anyway. No other changes in behaviour at home either, just to wear masks for any activities that can be done with masks in a space shared with other people. Those with beards don't need to shave their beards, they can use a badger clip.
500 of the households are randomly selected to wear masks. If 1 in 20 gets infected we can expect 25 households to have index cases, then we look for the difference in numbers of secondary infections in the households that did or didn't wear masks habitually at home during the outbreak. We use gene sequencing to confirm that these are indeed secondary infections from the index case.
The effects should be easily noticed if masks do indeed reduce transmission 5-fold or 10-fold or more.
It might be hard to find households to agree to wear masks at home in the West. It is much easier in Asian countries like Japan, China, South Korea. In the West households with immunocompromised members mght be interested. But it doesn’t matter if those 1000 households are selected out of a much larger survey, say of a million people, it will still be a valid RCT test of the effectiveness of masks.
Some in China wore masks habitually at home during the COVID pandemic in 2020 so it should be possible to find households in China interested to take part.
The aim is to use this method to quantify the EFFECTS of masks and based on that countries and individuals will have a good science basis to decide how they will use masks and in which situations. However it is possible that it could also be used as an intervention in some countries with high social acceptance of mask wearing, or that families might habitually wear masks at home especially if they share their household with vulnerable members, if the results are very clear as a result of this study. The maths suggests that if the results are at the very high end of the range of estimates, that a country with high levels of social acceptance of masks might even be able to achieve zero COVID through masks alone. It isn't 'necessary to be 100% effective. If masks can reduce transmision 10-fold the Re could be reduced from 8 (say) to 0.8 and any virus spread will quickly fizzle out just as it does for effective vaccines that stop most but not all transmission.
Anyway this is how it would work if we could find households to participate.
1000 households agree to wear masks if randomly selected - minimum 4 household members
500 households with masks, 500 without
Family with masks graphic from:family-masks-covid-19-corona-home
Selected households use FFP3 mask e.g. 3M aura, wear ONLY at home.
No other changes in behaviour.
Expect > 1 in 20 households to have COVID at Omicron wave peaks (since 1 person in 20 gets COVID)
At least 25 households in each group of 500 gets COVID.
Estimated secondary attack rate 1 in 4 for Omicron
Expect at least 25 to get COVID from household members without masks.
- Ssecondary attack rate 25% from: Secondary Attack Rates for SARS-CoV-2 Omicron and Delta Variants in Norwegian Households
- 1 in 20 at peaks Coronavirus (COVID-19) Infection Survey, UK
- Photo credit: Sandro Halank, Wikimedia Commons File:2021-12-07 Unterzeichnung des Koalitionsvertrages der 20. Wahlperiode des Bundestages by Sandro Halank–025.jpg - Wikimedia Commons
Physical modelling suggests easily detectable nearly 1000 fold reduction if all wear well fitted FFP2 masks. Observational studies suggest fabric masks reduce transmission about 5-fold.
- Physical modelling from paper here An upper bound on one-to-one exposure to infectious human respiratory particles
- 5-fold reduction study mentioned in CDC science brief on masks
QUOTE “In a study of 124 Beijing households with > 1 laboratory-confirmed case of SARS-CoV-2 infection, mask use by the index patient and family contacts before the index patient developed symptoms reduced secondary transmission within the households by 79%.”
CDC science brief on masks for COVID-19
At peak > 25 cases get COVID from household members in the 500 households without masks
If masks reduce secondary attack rate:
- 5 fold: 5 cases of household transmission in masked group.
- 10 fold: expect 2-3 cases of household transmission with masks
- 1000 fold: expect no cases in masked group.
If result are interesting repeat with - randomly selected schools (evidence of lots of transmission in schools) - larger trials of households - test effect of clinical masks, fabric masks, FFP2 (N95) etc - test eye protection
Masks graphic from WHO Getting the COVID-19 Vaccine
Household members with beards can use badger clips like I do, likely similar to yoga band, no need to shave.
For tests of eye protection can just use glasses or sunglasses though some wear wrap around eye protection like I do.
Text on graphic: 3M Aura FFP3 mask - equivalent to N99
- Shows use of badger clip for tight fit with beard - it’s tight enough so the mask moves in / out with my breath.
- Some studies suggest 10% of infection is via eyes - so with a high quality mask it may be worth wearing eye protection
- Probably enough to just wear glasses or sunglasses - I wear safety goggles for extra protection
This is the data about using a yoga band with beards to improve the efficacy of an FFP2 mask.
. Table 2 The effect of an elastic band worn over the beard on the fitted filtration efficiency of various face masks.
An RCT like this can lead to better informed decisions about whether to use masks or not, at individual, community or government levels. I suggested this RCT before here, new thing is to add graphics to make it clearer:
My own observation here. By high end of estimates, seems on paper possible to eliminate COVID from a country if 95% wear N99 or FFP3 masks (now widely available).
Whether anyone tries that or not, it is good to have hard data to know if one could use masks to eliminate COVID.
Others say ALL CDC's listed studies are flawed and believe correct figure is more like a few % reduction. Again we would want to know that if it is true.
We could also do challenge trials to find out. I'm no expert but I think my RCT would work, anyone expert able to comment?
So, IMHO we need much better data.
Including funding. Billions of dollars research into vaccines. How much funding for research into effectiveness of masks?
Once we have much better science, it should be easier to cohere around public health advice widely supported by experts.
Situation now is confusing for all.
Right now many wear masks out of a belief including expert opinion that they are very effective.
Others don't, again often mainly out of belief or expert opinion that they don't work.
So, top priority is to resolve this with science.
TITLES OF SECTIONS LIKE MINI ABSTRACTS - SUMMARIZE WHAT THEY SAY IN THE TITLE
I write titles of sections like mini abstracts - you can get a first idea of the article by reading just the titles and looking at the graphics - then drill into any section of special interest
HOW TO FIND A DEBUNK, OUR FACEBOOK GROUP, HELP IF SUICIDAL, ABOUT ME, PERMISSION FOR REUSE ETC
See: .How to find a debunk - Facebook group - help if suicidal - permission to re-use - about me - and other details from old space description
WE DON’T HAVE TO STOP ALL TRANSMISSION - WE CAN ELIMINATE A VIRUS BY BREAKING ONLY MOST CHAINS OF TRANSMISSION AND IT DOESN’T MATTER HOW IT IS DONE
Short explanation of how a pandemic spreads and how you can stop it by breaking chains of transmission without stopping all the cases. [I plan a longer article covering the many vaccines in development soon]
First this is how it spreads. In this toy pandemic each person infects exactly 2 others. Needs to infect at least 1 other for a pandemic.
Text on graphic: How pandemics happen. With an R₀ of 2 (each person infects 2 others) 1 person can infect 15 others after just 3 steps
It is much easier for a virus to spread inside the body than to get out of the body to a new human host.
Many viruses such as bird flu can get out of their animal host and jump to a human, but stop there as they can’t get out of a human body to another human.
Even if a virus sometimes jumps from human to human that’s not enough for a pandemic. To start a pandemic each person has ot infact at least one other on average
Most diseases that jump to humans stop themselves. In this toy outbreak only one person in 2 infects anyone else and infects exactly one other. Starting with 4 infected, after 2 steps they infect 7 and that's the outbreak over.
Diseases that stop by themselves
R₀ = 0.5, only 1 person in 2 infects anyone
Starting with 4 infected, after two steps they infect 3 more aqnd then its over, total 7 infected.
If R₀ <1 it isimpossible to spread as a pandemic.
If R₀>1 we can sometimes stop a pandemic if we break enough transmission.
That is how New Zealand, Taiwan, China and others were able to stop their local outbreaks of COVID in 2020.
How we can control and stop a pandemic.
Starting here we break 3 out of 4 chains of transmission with
- contact tracing
- hand hygiene,
- vaccination, etc (depending on virus and how it transmits)
The more chains you break the faster the pandemic stops.
Pandemic is over, controlled, no new infections.
This is how we controlled SARS, MERS, Ebola, without vaccines, and how New Zealand, Taiwan, China and several others controlled their outbreaks of ancestral COVID - also how vaccines work - does NOT need lockdown if you can break enough chains of transmission in other ways.
We had another chance of stopping COVID when Pfizer was developed- and had 95% efficacy at stopping even symptomatic disease, sterilizing immunity. Sadly Pfizer was only available to the stronger economies to start with. AZ was more generally available but there was still vast vaccine inequity and most places in Africa were only just starting large scale vaccination by the time Omicron came along
Pfizer, and Moderna couldn't stop enough Omicron to control those pandemics. HOWEVER we now have another shot at it. We have vast numbers of 2nd gen vaccines on their way. Some, especially mucosal (nasal spray) vaccines MIGHT achieve that 95% sterilizing immunity like Pfizer.
95% sterilizing immunity could control Omicron much like measles. Break so much transmission outbreaks are self limiting and stop quickly. We could also help it along with other methods - masks, contact tracing etc COMBINED with a much more effective vaccine could stop COVID.
Text on graphic: Be sure to get your booster as the effect of the vaccine wanes much more than for most vaccines - next gen vaccines may be better
Masks help reduce your risk
- eye protection may help too
- if you get it less often you have less risk of long COVID, severe disease or death
PFIZER WAS 94% EFFECTIVE AT STOPPING ASYMPTOMATIC INFECTION FOR THE ALPHA VARIANT, B1.1.7
I covered that in my blog post before here:
. More excellent vaccine news - Pfizer stops alpha variant B.1.1.7 variant (97% effective) and stops transmission (94% at preventing asymptomatic cases of alpha)
NOVAVAX STOPS 90% OF SYMPTOMATIC COVID IN ONE TRIAL - NOT FAR OFF THE EARLY RESULTS OF PFIZER AND MODERNA AGAINST ANCESTRAL
Data from Novavax already says it stops 90% of SYMPTOMATIC COVID.
. Phase-3 trials of Novavax's vaccine show high levels of protection against infection: Research head
Which makes it a bit puzzling the low uptake of Novavax in countries that have approved it. They tend to prioritize Pfizer over Novavax.
WE ELIMINATE MEASLES WITH A VACCINE ABLE TO STOP 97% OF INFECTON - WITH RESULTS AS GOOD AS PRIZER AGAINST ALPHA WE COULD ELIMINATE COVID TOO
Next gen vaccines may be able to reduce it to levels more like measles if we get results as good as Pfizer against ancestral COVID.
Two doses of MMR vaccine are 97% effective against measles.
. Measles, Mumps, and Rubella (MMR) Vaccination
The measles R0 is higher than for Omicron (though Omicron has a faster generation time).
So if we get to 95% or higher we can likely stop Omicron like measles. Indeed - even at lower levels countries would be able to manage and stop outbreaks with just contact tracing, isolation and quarantine only of the infected people. Countries like China or New Zealand might try that first.
WE HAVE ELIMINATED MANY OF THOSE DISEASES THAT TROUBLED HUMANITY IN 1900 - SOME ALMOST COMPLETELY - FLU IS THE ONLY HYPERENDEMIC DEADLY DISEASE LEFT
Smallpox has been eradicated from the world.
Many countries are measles free (only imported cases and transmission locally lasts for less than a year). The UK recently lost its measles free status but the US still has it.
But cases of measles per year in the UK are very small. UK lost measles elimination status at 991 confirmed cases in 2018 (later updated to 998)
Globally deaths due to measles continue to fall.
Tuberculosis is just about gone as a result of modern antibiotics.
We have more than halved mortality from all causes since 1900 and most of that change is due to eliminating most of the most deadly infectious diseases and greatly reducing the deaths from flu.
Reduction in infectious diseases 1900 to 2010. Only influenza is left of the hyperendemic diseases, greatly reduced
See: Mortality and Cause of Death, 1900 v. 2010 | Carolina Demography
Now the only hyperendemic disease left is flu, to which we have now added COVID.
COULD CHINA ELIMINATE COVID WITH HIGH QUALITY MASKS TAKING THE PLACE OF LOCKDOWNS, TRAVEL QUARANTINE AND QUARANTINE OF CONTACTS?
Recently I've been wondering if it is possible to eliminate COVID using high quality FFP3 masks alone. If you take the high end of the data it seems possible and might be an option for China during outbreaks??
That’s because if you use physical modeling, if everyone wears FFP3 masks it could reduce transmission as much as several hundred fold for well fitting masks.
Could China continue with zero COVID with high quality masks instead of lockdowns?
If they open up it could lead to several million deaths in a short time even with vaccines.
But if the best quality masks are as good as physical modelling suggests, they could break enough chains of transmission to replace quarantine of contacts, lockdowns and travel quarantine.
- nearly as good as these full body suits.
Background graphic from: :Jordan lockdown view1 20210123.png - Wikimedia Commons
It might be possible right away, and especially later, added to a mucosal vaccine.
The idea is that masks + vax could permit relaxing travel restrictions and remove need for lockdowns similarly to a better vaccine. Many Chinese wear masks in public and during Wuhan outbreak wore them at home, it wouldn't be a difficult thing for them to adopt.
The idea is as for a vaccine, wearing masks breaks enough chains of transmission that outbreaks quickly fizzle out. Also because they act instantly, not wih 10 days delay they could wear FFP3 masks as soon as 1st cases are reported and immediately break almost all transmission.
And as for a 95% effective vaccine there would be outbreaks, like there are outbreaks of measles, but they would quickly fizzle out every time. It could be a bit like if one country has 95% measles vaccination and rest of the world unvaccinated. It would have very few cases.
It's just a thought. If any country could control COVID and keep total cases very low close to Zero COVID levels using masks as the main control measure, even if vaccines don't stop much transmission, China seems likely. Or Taiwan, Singapore, Japan - Asian countries generally.
It might also end the need for quarantine of contacts. Isolation of cases taken for granted + early diagnostics. But if FFP3 masks really stop almost all transmission, contacts continue to go to work but wear masks as do their co-workers which isn't hard for Chinese.
Quarantine of contacts + lockdowns being the main things economically distruptive. Maybe replaced by masks. Otherwise identical to what they do already. Travel quarantine perhaps replaced by requirement to wear a mask for 2 weeks after entering the country?? Just thoughts.
VACCINES PLUG GAPS IN PUBLIC HEALTH AND VICE VERSA
This is a graphic I did before back when it was feasible to eliminate COVID with a combination of vaccines and publilc health without the very strict measures China uses - through to the emergence of Omicron, this was possible, as New Zealand showed.
Vaccine plugs gaps
Not washing hands
Excellent public health
stops virus without vaccine
World image from here
Weaker COVID health response
Like armour with holes in it
Stops only some transmission
Vaccine plugs gap
Best COVID response - like the highest quality armour
Stops all transmission without a vaccine.
Right hand image is the armour for King Henry VIII, of the highest quality.
Left hand image - Spartan helmet from the British Museum with nail holes at the top and cheek holes which show it has been a trophy.
With Pfizer / Moderna / Astrazeneca they just don’t stop enough of the transmission for Omicron to do much to stop or slow down the spread of COVID though they are very effective at greatly reducing severe disease, hospitalization and death.
If we get a better vaccine, even if it doesn’t stop enough transmission to eliminate COVID on its own - it might reduce it far enough to make it possible to eliminate it from a country by combining vaccines with public health measures during outbreaks.
The other way around , a good enough mask may be enough of a public health measure to reduce the gaps that the vaccine needs to provide and together block enough transmission to stop spread.
COULD WE DO A MULTI-VACCINE TRIAL TO TEST ALL OUR CURRENT VACCINES AGAINST EACH OTHER FOR EFFECTIVENESES IN STOPPING TRANSMISSION?
From the novavax data it seems not impossible that Novavax could stop enough transmission for a zero COVID policy if combined with masks in China - it might be worth considering evaluating our current vaccines to see which stops most transmission in addition to the evaluation of which stops most severe disease and death.
Ideally we need a multi-vaccine trial where people are randomly given any of the current vaccines, Pfizer / Moderna / Astrazeneca / Novavax / etc.
The WHO multi-vaccine trial in Africa does that with all the vaccines it’s testing but tests them against a placebo that does nothing.
If our aim is to eliminate COVID locally - it would be great to do a multi-vaccine trial where the control groups are given Pfizer / Moderna to see if any of our vaccines are better at stopping transmission than Pifzer / Moderna - though there may be issues getting permission from Pfizer / Moderna to do such a trial.
Since Pfizer / Moderna seem to stop almost no transmission of Omicron the results might be quite striking from a multi-vaccine trial with them as placebo against the new mucosal vaccines - whiel it would still be ethical even in countries with widespread availability of vaccines.
In my longer version of this article I go into some of the amazing advances in the COVID vaccines. Especially the mucosal vaccines - if they live up to their promise. This is my concluding section:
IN THE FUTURE - WHO KNOWS - MAYBE A FUTURE WITHOUT EVEN FLU OR FLU VERY RARE?
So what will we see in the future? Will deaths from infectious diseases go down even more?
Well we are seeing amazing advances in vaccines.
We are seeing amazing advances in technology for vaccines and theerapeutics in the COVID pandemic.
In the cities of the future will flu and colds be unknown - or as rare as measles is for us today?
City graphic from Living on Earth: The Well-Tempered City, creative commons, non commercial, non derivative (adding the caption below the picture I think is okay).
With amazing advances in vaccines for COVID, pancoronavirus vaccines etc, a universal flu vaccine might not be that far away? End of century? Mid century? Next decade?
LONGER ARTICLE WHICH FOCUSES ON NEXT GEN VACCINES IN CLINICAL TRIALS WHICH MAY BE ANOTHER WAY TO ELIMINATE COVID LOCALLY IF COUNTRIES ADOPT THEM
There are dozens of vaccines in clinical trials Mucosal vaccines are especially interesting. They stimulate tissue-resident immunity in the mucosal membranes of the nose, mouth, respiratory tract and stomach. If they work then they can stop the virus before it gets into your blood, much earlier than the intramuscular vaccines which for some reason don’t stimulate tissue resident immunity in the mucosal membranes to anything like the same degree.
Some experts think that mucosal vaccines might achieve close to 100% sterilizing immunity - blocking the virus before it can infect you. This would not only stop all or nearly all hospitalization and severe disease and death but also long COVID and it could be enough to reduce cases to a few per year as for measles. We can’t eradicate COVID now as it has too many animal reservoirs around the world. But as for yellow fever we could eliminte it in humans.
COVID only jumps to humans rarely, no known cases in China throughout the pandemic after the initial outbreaks. With vaccines - or with high quality masks - or both - we could stop any such outbreaks very quickly.
This uses sections from my longer article here where I also go into mucosal and pancoronavirus vaccines research.
Text on graphic: If you want to stop transmission with respiratory virus you really should be trying to induce an immunity in the respiratory pathway in the lining of the the nose, the lining of the throat the lining of the lung, and really the only way to do that effectively is to give some kind of a nasal spray that contains a vaccine.
Dr Mike Ryan, executive director of WHO Health Emergency Program.
Longer quote on graphic:
We've not developed broadly for respiratory infections we've tended to stick with the injectable vaccines to prevent illness because the purpose of an influenza vaccine is not really to prevent transmission it's meant to stop a person who is vulnerable from having a severe influenza disease and at that level it works very well.
If you want to stop transmission with respiratory virus you really should be trying to induce an immunity in the respiratory pathway in the lining of the the nose, the lining of the throat the lining of the lung, and really the only way to do that effectively is to give some kind of a nasal spray that contains a vaccine.
They certainly could be game changers because what they do is give you that broad-based mucosal immunity preventing the infection in the first place and that would in effect potentially be able to stop transmission but it depends how effective they are in stopping that transmission.
They could also be much cheaper because oral vaccines or nasal vaccines you're not injecting something into the body so there can be much more mass-produced and very often have a stronger safety profile so I think there are a lot of advantages but it remains to be seen how fast we get them. And then will the demand be there will there will there be a market for those vaccines for the companies to sell?
Dr Mike Ryan (WHO): why nasal spray vaccines could be a game changer if they can indeed stop COVID transmission - could they be China’s way out of Zero COVID or even eliminate COVID locally similarly to measles vaccines?
HOW TO FIND A DEBUNK, OUR FACEBOOK GROUP, HELP IF SUICIDAL, ABOUT ME, PERMISSION FOR REUSE ETC
This is from my Quora blog which I do to help people who are scared by news stories.
I have a list of all the debunks - you can search the titles - or you can search the blog with a google search.
We have a facebook group that you can join to either help scared people with your debunks or to ask for help if scared, or help the scared people in other ways.
I also have a blog post about how to help people who are suicidal - and this page also has some details about me and permission to resuse this content.
See: . How to find a debunk - Facebook group - help if suicidal - permission to re-use - about me - and other details