Follow the science?

I’ve got a mask. I don’t need a flu shot, right?

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I’ve got underwear so I don’t need pants right? Follow the science sheeple.

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Belts and suspenders?

Belts and suspenders and Underoos!

That’s not a mask for this pathogen, Dr. Redfield.

When I hear the argument “masks work”, or “masks don’t work”, I know they don’t know what they are talking about.

Here is some data you will need:

pathogens
diameter of Rhinovirus 25-30 nm
dia of Influenza 80-120 nm
dia of Coronavirus 90-120 nm
width and length of Anthrax 1000-1500 nm X 3000-10000 nm
dia of Streptococcus 600-1000 nm

filtration of masks
surgical mask 95% at 2500 nm
N95, KN95, FFP2, GB2626 masks 95% at 300 nm
Soom Labs nanofiber 99% at 100 nm

Now you can make a reasonable judgement of the mask you will need, when in the presence of a given germ.

Anthrax – Surgical Mask
Strep – N95, KN95, FFP2, GB2626
Coronavirus and Influenza – Soom Labs (99%)
Rhinovirus – luckily these aren’t so deadly, because when aerosolized, we don’t have a mask to effectively block a Rhinovirus

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So you do understand that the efficiency ratings for masks (e.g., 95%) is for the worst measured efficiency for the most poorly performing particle size, right? Masks filter particles smaller and larger than that worst size with higher efficiency than the stated rating.

A common misconception is that masks merely act like sieves and anything smaller than the “holes” in the mask will easily pass through. The mocking analogy du jour, created by some uneducated dolt, is that it’s like trying to stop mosquitoes with a chain link fence. That’s incorrect and simply betrays a lack of knowledge of how masks function.

Also, virus particles don’t typically leave someone’s respiratory tract as lone particles, but as part of a larger (relatively speaking) droplet of liquid. That is the reason for the suggestion that even simple inefficient masks can protect others, through source control before the droplets can be released and evaporate into smaller particles that travel further and linger longer.

Something else to consider is that initial viral dose has an effect on disease severity and progression. With all viruses it takes some >x number of virus particles to “break through” the initial immune response to start an infection, and a large dose seems to break through more quickly and leads to a higher viral load throughout the infection. Studies are sparse but anecdotal evidence of severe infection in otherwise healthy healthcare workers, who when exposed are exposed in close proximity to sick, symptomatic patients seems to support this. So even masks that don’t block everything might help just by reducing the initial exposure to something your system has time to start dealing with.

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A corollary to the arguments “masks do/don’t work” is the blanket statement “masks do/don’t block viruses”.

Under normal conditions (people breathing normally), almost any mask (even a homemade cotton mask) will catch respiratory droplets. But, if an infected person sneezes or coughs, the virus can be ejected from the moisture droplets and become aerosolized. Now, everything changes, aerosolized viruses can travel across the room, or stay suspended in the air for several minutes. The same can happen when a patient is intubated on a High-PEEP ventilator, the exhaust is rich in aerosolized virus.

Once Aerosolized, a virus doesn’t travel in a straight line. They bounce off dust and air particles in a Brownian motion (like a Lotto Ball). This is one of the reasons why N95 masks are still partially effective against Coronavirus. The virus gets tangled up in the filtering element because it is bouncing in a very erratic pattern.

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Yup. The largest particles are simply trapped like in a sieve. Smaller than that and they are trapped by impingement, where their mass is too great to follow the air current through the twists and turns through the filter and they end up slamming into a fiber and getting stuck. The very smallest are light enough to be trapped through electrostatic attraction to the mask fibers.

Read something recently but don’t have a link. Some tests where they “charged” a mask by rubbing with a rubber glove and found greater efficiency that lasted for hours. I’m not sure if it was a published study - I just read a blurb about it.

Here is an interesting study (2013) on mask effectiveness and a viable but harmless test virus (MS2). Note that MS2 particles themselves are much smaller (~5-10x) than SARS CoV-2, but mask performance exceeded the stated ratings on the masks:

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Masks work.

I have never been arrested.

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It appears that measures to fight coronavirus have practically eliminated the flu season in the southern hemisphere.

That’s pretty cool. Though I think most people would rather get a vaccine and go back to the before times if given a choice. Both approaches have pros and cons.

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I can’t find the source, but I recall reading that it takes approximately 3000 viral particles introduced in a single dose / extremely short time period via a common pathway for an infection to take hold - fewer or diffuse vectors for infection result in preemptive immune response or the particles fail to connect with a target receptor and get ejected/broken down like other particles that end up in your lungs with every breath. PPE that would be wholly inadequate for occupational exposure - where there are known large volumes of pathogens in the local environment - will more than suffice for casual exposure (i.e. the grocery store) so long as the number of infected are few and measures are taken to minimize exposure.

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This is an interesting but not unsurprising finding. By that I mean that this shows that making an effort to avoid transmission of disease works. If nothing else, we can point to this for our more at risk population, and encourage them to consider face masks, hand washing and social distancing during the flu season especially during a particularly bad flu season. It also might indicate that if we visit our elderly parents or at risk friends during flu season, we should practice some of these measures. Remember, that even with a vaccine there is significant morbidity and mortality during a typical flu season.

Thanks for posting this.

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One issue with the flu vaccine is that they’re always guessing. “Flu” comes in a variety of strains, and they’re always guessing which strain might be this year’s strain when they vaccinate folks. One of the things that’s come up in the discussions this year is that even the wrong flu vaccine might help you out. Not as much as being vaccinated against the specific flu, but some.

One of the reasons that I’ve never felt like getting the flu vaccine. It’s too vague.

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I always get a flu shot. Doesn’t always work. I got the flu - possibly for the first time - in the 2018 outbreak. That one was apparently not covered by that year’s shot.

After that week of being miserable, I’m MORE inclined to get the flu shot. Some protection is better than none on that front.

Likewise I’ll get the covid vaccination when it comes out. I’m not going to be first in line, but I’m sure I’ll get one eventually.

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They do the best they can.

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I get that. And the something is better than a nothing. Still – not worth my bucks.

@tmc4242 – and in a measure of irony this year, one of the Block employees got the flu from one of her customers. Not COV19 – the flu…

I’m not sure if I’m just lucky, or if my over-active immune system has saved me, but I don’t think I’ve ever had the flu.

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My daughter (BNS) tells me to always get the Flu shot, because they include in the cocktail a current H1N1, and you never want to get H1N1 (the organ damage will affect the rest of your life).

So I get the shot partially because I don’t want to get a full-blown case of whatever is going around, and so I can ease her mind when she checks on me.

Here is the breakdown for 2019-2020 from CDC:

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I once had a boss who was anti-vax because one time, he got a flu shot, then got food poisoning two days later. No, I’m not saying that he got food poisoning, and misdiagnosed himself with the flu. He knew that it was food poisoning (according to him, it was from a chinese buffet), he just thought that the flu shot should have kept him from getting sick.

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That is so 2019…using serving utensils others have touched.

I hope the buffet is not permanently gone. They can either have staff do the serving or place a box of thin plastic gloves at the head of the serving line where the plates are stacked.

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I wonder how many anti-maskers would be vocally anti-mask if they were being prepped for surgery? “Hey, you! Fancy-pants cardiothoracic surgeon! Get that useless mask off!”

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