Vaccine

dad4 said:
You misread the study.

All masks worked to redirect the plume. Some worked as filters, some did not.

From the study:

"Measurements demonstrate that all tested masks provide protection in the immediate vicinity of the host primarily through the redirection and reduction of expiratory momentum. However, leakages are observed to result in notable decreases in mask efficiency relative to the ideal filtration efficiency of the mask material, even in the case of high-efficiency masks, such as the R95 or KN95. Tests conducted in the far field (2 m distance from the subject) capture significant aerosol build-up in the indoor space over a long duration (10 h). "

aip.scitation.org

Experimental investigation of indoor aerosol dispersion and accumulation in the context of COVID-19: Effects of masks and ventilation

The ongoing COVID-19 pandemic has highlighted the importance of aerosol dispersion in disease transmission in indoor environments. The present study experimentally investigates the dispersion and b...
aip.scitation.org

Interestingly, the study also indicates that good ventilation may be a more effective choice than upgrading everyone's mask.

"The results also suggest that, while higher ventilation capacities are required to fully mitigate aerosol build-up, even relatively low air-change rates (2 h−1) lead to lower aerosol build-up compared to the best performing mask in an unventilated space."
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“Impact of non-pharmaceutical interventions against COVID-19 in Europe: a quasi-experimental study”

“The current epidemic of COVID-19 is unparalleled in recent history as are the social distancing interventions that have led to a significant halt on the economic and social life of so many countries. However, there is very little empirical evidence about which social distancing measures have the most impact… From both sets of modelling, we found that closure of education facilities, prohibiting mass gatherings and closure of some non-essential businesses were associated with reduced incidence whereas stay at home orders and closure of all non-businesses was not associated with any independent additional impact.”
 
dad4 said:
Particle reduction? You’re still thinking of masks as filters. Ask whether the mask redirects air flow away from the receiving person. It’s a better question.

Then, if you are indoors, ask what the ventillation system does to trap or expel the virus before it builds up on the room.

I agree that, if you are in a poorly ventilated room with lots of people, you need an N95. But you also need to ask yourself why you are in that room at all.
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EYE ON THE NEWS Do Masks Work? A review of the evidence Jeffrey H. Anderson August 11, 2021

“Seriously people—STOP BUYING MASKS!” So tweeted then–surgeon general Jerome Adams on February 29, 2020, adding, “They are NOT effective in preventing general public from catching #Coronavirus.” Two days later, Adams said, “Folks who don’t know how to wear them properly tend to touch their faces a lot and actually can increase the spread of coronavirus.” Less than a week earlier, on February 25, public-health authorities in the United Kingdom had published guidance that masks were unnecessary even for those providing community or residential care: “During normal day-to-day activities facemasks do not provide protection from respiratory viruses, such as COVID-19 and do not need to be worn by staff.” About a month later, on March 30, World Health Organization (WHO) Health Emergencies Program executive director Mike Ryan said that “there is no specific evidence to suggest that the wearing of masks by the mass population has any particular benefit.” He added, “In fact there’s some evidence to suggest the opposite” because of the possibility of not “wearing a mask properly or fitting it properly” and of “taking it off and all the other risks that are otherwise associated with that.”
 
dad4 said:
It’s

That article is just not very well thought out. It jumps to dramatic contrarian positions very quickly, without bothering to scope out the problem space.

For example, it presents impressive sounding numbers about asymptomatic infections of vaccinated people. Why do we care about asymptomatic infections? She doesn’t say. What kind of spread is occurring from symptomatic cases? She does a half hearted back of the envelope swag to assert that it must be large.

Then more of the same. She repeated gives half an argument, but presents it as a definitive conclusion.

Reads like this forum.
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“Lockdowns and Closures vs COVID – 19: COVID Wins” by Surjit S Bhalla, executive director for India of the International Monetary Fund.

“For the first time in human history, lockdowns were used as a strategy to counter the virus. While conventional wisdom, to date, has been that lockdowns were successful (ranging from mild to spectacular) we find not one piece of evidence supporting this claim.”
 
dad4 said:
LA's rules sound ok. Masks and vaccines have solid evidence behind them. Let me know when a high vax city (above 80% for over 12) goes beyond vaccine passports.

Hawaii sounds like they want to blame the tourists for community spread. Closing beaches does a good job of driving away tourists, but it won't solve their covid problem.
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Effects of non-pharmaceutical interventions on COVID-19: A Tale of Three Models

Abstract

Objective To compare the inference regarding the effectiveness of the various non-pharmaceutical interventions (NPIs) for COVID-19 obtained from different SIR models.

Study design and setting We explored two models developed by Imperial College that considered only NPIs without accounting for mobility (model 1) or only mobility (model 2), and a model accounting for the combination of mobility and NPIs (model 3). Imperial College applied models 1 and 2 to 11 European countries and to the USA, respectively. We applied these models to 14 European countries (original 11 plus another 3), over two different time horizons.


Results While model 1 found that lockdown was the most effective measure in the original 11 countries, model 2 showed that lockdown had little or no benefit as it was typically introduced at a point when the time-varying reproductive number was already very low. Model 3 found that the simple banning of public events was beneficial, while lockdown had no consistent impact. Based on Bayesian metrics, model 2 was better supported by the data than either model 1 or model 3 for both time horizons.

Conclusions Inferences on effects of NPIs are non-robust and highly sensitive to model specification. Claimed benefits of lockdown appear grossly exaggerated.


Cherry Picking season was over in May!!
 
Grace T. said:
The waterloo study answered that question as well. Through the material, the cloth masks had only a 50% reduction. If someone just sneezed behind you on a bus, airplane or classroom, that cloth mask isn't doing much (surgical better).
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You mean this:

"more than 50% of aerosols (polydisperse, 1 μm mean diameter) can pass through the material of commercially available cloth and surgical masks in ideal conditions"

That is still just talking about filtration efficiency, not breath redirection. You have to include both. The same paper still claims that overall transmission reduction is 70-80%.
 
Grace T. said:
Locals in Hawaii tend to have large gatherings at the beaches since houses tend to be small and there is a water culture.
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Super Spreaders Hawaiian Style....lol All kidding aside. The locals my bro knows hunt for wild Boar 4 days a week and because house is small and they need to earn a living, they share the pig with a hotel and then charge the tourist $49.95 each ((kids under 3 eat free)) to experience a real luau. My wife's cousins go out and sell the tickets for the luau and also take a part in the dances and one of them sings Don Ho music. Super good looking guys and look the part. Hotel makes some of the profits as well. My wife's cousins grew up in East LA and also take tourist on exclusive sight seeing tours and have a blast. PM me if any of you need help to explore the finer things in back country. Super cool guys and we all get a good laugh when we catch up. They do "lie" a little and tell a story of how their true blooded locals. It's just part of the tour and nothing else. They actually look more local then the real locals, moo :)

1629856226377.png
 
dad4 said:
Why would the existence of a booster shot make lockdowns more likely?

I don’t think you’ll see many more business closures. High vax areas aren’t getting large enough spikes to provoke lockdown discussions. Low vax areas don’t have political support for business closures.

Short of a truly vaccine resistant variant, i would bet businesses stay open.
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“Assessing Mandatory Stay‐at‐Home and Business Closure Effects on the Spread of COVID‐19” by Eran Bendavid, Christopher Oh, Jay Bhattacharya, John P.A. Ioannidis. European Journal of Clinical Investigation, January 5, 2021.

“Implementing any NPIs was associated with significant reductions in case growth in 9 out of 10 study countries, including South Korea and Sweden that implemented only lrNPIs (Spain had a non‐significant effect). After subtracting the epidemic and lrNPI effects, we find no clear, significant beneficial effect of mrNPIs on case growth in any country. In France, e.g., the effect of mrNPIs was +7% (95CI ‐5%‐19%) when compared with Sweden, and +13% (‐12%‐38%) when compared with South Korea (positive means pro‐contagion). The 95% confidence intervals excluded 30% declines in all 16 comparisons and 15% declines in 11/16 comparisons.”
 
dad4 said:
You mean this:

"more than 50% of aerosols (polydisperse, 1 μm mean diameter) can pass through the material of commercially available cloth and surgical masks in ideal conditions"

That is still just talking about filtration efficiency, not breath redirection. You have to include both. The same paper still claims that overall transmission reduction is 70-80%.
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“Lockdown Effects on Sars-CoV-2 Transmission – The evidence from Northern Jutland”

The exact impact of lockdowns and other NPIs on Sars-CoV-2 transmission remain a matter of debate as early models assumed 100% susceptible homogenously transmitting populations, an assumption known to overestimate counterfactual transmission, and since most real epidemiological data are subject to massive confounding variables. Here, we analyse the unique case-controlled epidemiological dataset arising from the selective lockdown of parts of Northern Denmark, but not others, as a consequence of the spread of mink-related mutations in November 2020. Our analysis shows that while infection levels decreased, they did so before lockdown was effective, and infection numbers also decreased in neighbour municipalities without mandates. Direct spill-over to neighbour municipalities or the simultaneous mass testing do not explain this. Instead, control of infection pockets possibly together with voluntary social behaviour was apparently effective before the mandate, explaining why the infection decline occurred before and in both the mandated and non-mandated areas. The data suggest that efficient infection surveillance and voluntary compliance make full lockdowns unnecessary at least in some circumstances.”
 
Bruddah IZ said:
“Lockdown Effects on Sars-CoV-2 Transmission – The evidence from Northern Jutland”

The exact impact of lockdowns and other NPIs on Sars-CoV-2 transmission remain a matter of debate as early models assumed 100% susceptible homogenously transmitting populations, an assumption known to overestimate counterfactual transmission, and since most real epidemiological data are subject to massive confounding variables. Here, we analyse the unique case-controlled epidemiological dataset arising from the selective lockdown of parts of Northern Denmark, but not others, as a consequence of the spread of mink-related mutations in November 2020. Our analysis shows that while infection levels decreased, they did so before lockdown was effective, and infection numbers also decreased in neighbour municipalities without mandates. Direct spill-over to neighbour municipalities or the simultaneous mass testing do not explain this. Instead, control of infection pockets possibly together with voluntary social behaviour was apparently effective before the mandate, explaining why the infection decline occurred before and in both the mandated and non-mandated areas. The data suggest that efficient infection surveillance and voluntary compliance make full lockdowns unnecessary at least in some circumstances.”
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In other words the freak out is more important than the lockdown. I seem to recall saying that.
 
watfly said:
So you're OK if your speaking to someone face to face but if there is anyone next to them they're screwed? IDK, I didn't read the study. Where does the redirected plume go?
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Well if you are speaking to them face to face 50% of the material is still going through. That plume is still being dispersed but instead of shooting straight is moving in a cloud around the front and sides of the mask. So, if someone is standing in front of you talking and sneezes, it may reduce the viral load you directly inhale but both you and the person standing next to you chatting is still getting plenty of virus, and with the Delta more than likely enough to make them sick.
 
Wall Street Journal columnist Jason Riley decries the confusion and excessive risk aversion that mars school openings across America. Two slices:

The officials in charge of running the nation’s public schools had all summer—and $122 billion in Covid relief funds from Congress—to plan for the first day of school, so naturally chaos has ensued as students begin heading back to the classroom.
…..
The Rand Corp. has released the results of a nationwide parent survey on school hesitancy taken in July. Although Delta was already spreading by then, 89% of parents, including more than 80% of typically more hesitant black and Hispanic respondents, said they would opt for in-person learning for their children this year. Parents apparently understand the health risks, and they’re weighing them against the harm of another year of horribly substandard instruction via Zoom.
 
dad4 said:
Your breath is warm. Within a few seconds, convection takes it up. From there, it mixes with the rest of the room.
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Bryan Caplan masterfully unmasks shoddy reasoning about masking. A slice:

Personally, I only find masks marginally uncomfortable. But I hate wearing them, and I dislike being around people who wear them. Why? Because a big part of being human is showing other people our faces – and seeing their faces in return. Smiling at a stranger. Seeing your child laugh. Pretending to be angry. Seeing another person’s puzzlement. Masks take most of those experiences away. At the same time, they moderately reduce audibility. Which further dehumanizes us. How many times during Covid have you struggled to understand another person? To be heard? Indeed, how many times have you simply abandoned a conversation because of masks? I say the dehumanization is at least five times as bad as the mere discomfort. And if you reply, “Want to see other people’s faces and hear other people’s voices? Just Zoom!,” I will shake my head in sorrow that you’re dehumanized enough to say such a thing.

Am I just being a big baby about this? I think not. Suppose humanity could eliminate all disease by wearing bags over our heads forever. Would you be willing to go through life not seeing the faces of your children? Would you want your child to go through life not seeing the faces of their friends? Well, during Covid we’ve moved at least 25% in that dystopian direction. The word “hellscape” is not out of place. I’ve never been a fan of the veiling of women, but I had to live through Covid to realize how horribly dehumanizing the custom really is.
 
Grace T. said:
Well if you are speaking to them face to face 50% of the material is still going through. That plume is still being dispersed but instead of shooting straight is moving in a cloud around the front and sides of the mask. So, if someone is standing in front of you talking and sneezes, it may reduce the viral load you directly inhale but both you and the person standing next to you chatting is still getting plenty of virus, and with the Delta more than likely enough to make them sick.
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50% of the virus gets through a cloth mask, but it’s hanging out within a few inches of your face. Not yet a risk to anyone unless you like to be 18 inches away from your conversational companions. If that’s the case, back off a little.

Sneezing is a separate question, but it’s a red herring in this context. Most covid transmission is believed to be related to normal speech and breathing. But, if you’re worried about your sneezes, a mask also reduces the distance you can sneeze.
 
dad4 said:
50% of the virus gets through a cloth mask, but it’s hanging out within a few inches of your face. Not yet a risk to anyone unless you like to be 18 inches away from your conversational companions. If that’s the case, back off a little.

Sneezing is a separate question, but it’s a red herring in this context. Most covid transmission is believed to be related to normal speech and breathing. But, if you’re worried about your sneezes, a mask also reduces the distance you can sneeze.
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So sad that you've been reduced to the Science of sneezing.
 
dad4 said:
50% of the virus gets through a cloth mask, but it’s hanging out within a few inches of your face. Not yet a risk to anyone unless you like to be 18 inches away from your conversational companions. If that’s the case, back off a little.

Sneezing is a separate question, but it’s a red herring in this context. Most covid transmission is believed to be related to normal speech and breathing. But, if you’re worried about your sneezes, a mask also reduces the distance you can sneeze.
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What's the difference between 50% of the virus hanging out within inches of your face and having 100% of the virus hanging out within inches of your face if your not having close conversation? Are you saying that the cloth mask keeps keeps the virus closer to your face?
 
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