I've had funny conversations about why I still wear a good n95 on public transit (planes included). My right-leaning and remarkably well educated parents are incredulous.

A few years ago I thought personal masking didn't really matter. Wow, I was wrong! And not catching bs colds from weirdos on the bus or the grocery store makes it worth it.

My face isn't that pretty anyway.

They might be right about the actual plane ride because the filtration systems on modern (read 20 years old or newer) are really good. Public busses tend to be a disaster for air filtration though, especially in winter when no windows are open. I wish there was some better research/more accessible research on this.

Even if the plane's filtration is good, if the person 3 feet away from you is coughing it's not going to be that good. I'd rather rely on the combination of filtration & a mask. Defense in depth.

Day to day i'm not religious about masking, but for things like public transportation, airplanes, etc I try to always have face protection on.

Pressurized airplanes have air changes per hour in the 12-16 range. That's above the ASHRAE recommended 6-12 air changes per hour for places that may contain viruses. (Obviously, ASHRAE isn't the CDC or healthcare organization directly, but they do know a few things about standards setting for HVAC.) Excellent filtration isn't as relevant when the average air molecule is in the aircraft for only 5-10 minutes.

The standard for AC/H for offices is 3-4.

The studied COVID outbreaks on planes show that this still isn't sufficient. I'm also pretty sure I got sick from the kid sitting directly behind me on the plane when I got influenza.

You can site all the statistics and propaganda in the world about plane ventilation. It clearly isn't enough to prevent viral spread (I don't care about air changes per hour or cfm or anything else, the only endpoint worth discussing is viral spread--I give precisely zero fucks about how fast the air is moving around). I'm using n95s on planes from here on out.

The real hazard is when you're on the ground. I've seen cabin C02 levels above 3000ppm when the cabin air handling hasn't been turned on!

I'll take my mask off to eat/drink in the air, which I didn't do the one time I had to fly mid-pandemic.

anecdotally, this is marketing bs / wishful thinking.

I've been on a handful of flights in the last 2 years where the air system didn't work at all, and others where the climate control system was otherwise failing (80°F). This is accentuated by stale air when you embark and disembark when the aux generators aren't providing power.

How old were the planes that this happened on? There has definitely been a dramatic improvement over the years. I remember flying in the 90's and pretty uniformly feeling like I needed at least a good face wash, if not a shower after any flight longer than a half hour. Now this only happens when I am unlucky enough to get stuck on an old aircraft (i.e. the original westjet 737's still get me with this). I swear I saw a paper on this being tested showing particle diffusion on some newer crafter being really impressive for how it kept your particles around you until they were removed and replaced with fresh ones fairly quickly but I can't remember enough to find a link to the study to back this statement up.

These flights were in the last 2 years on a top tier (US though) carrier on domestic flights; 1 was a very regional flight, where , as you post, an older plane might expect it -- but if anything, that any planes in a top tier carrier that markets itself as Covid ready are expected to be bad is typical of how much bs this is.

Yep. I went from being sick roughly one week out of every 1-2 months before covid to only getting sick maybe once a year now that I mask in public places, thoroughly wash my hands with soap every time I arrive somewhere, and occasionally wash my phone. Never going back. This whole "train your immune system" thing is BS. Hygiene is important!

I muse to myself ... masks do in fact "train your immune system". Since they are no where near perfect, pathogens do make it though. However, the "initial viral load" is much smaller, giving your body more time to mount an effective defense. So, I would like to believe you are not neglecting your immune system by masking, but rather just being less sick, on average.

I want to carry you on my shoulders among a cheering crowd.

> However, the "initial viral load" is much smaller, giving your body more time to mount an effective defense.

That's a myth from the early pandemic. Viral dose doesn't correlate with disease severity:

https://medicalxpress.com/news/2021-11-relationship-viral-do...

But:

the likelihood of becoming infected may rise with the size of that "dose."

So a small dose might still prime the immune system even if you don't get sick.

> the likelihood of becoming infected may rise with the size of that "dose."

This is correct.

> So a small dose might still prime the immune system even if you don't get sick.

This does not follow.

If you don't get infected following a small dose, you'll have fought it off with your innane or intrinsic defenses. You won't generate any humoral immunity, form T-cells or B-cells or neutralizing antibodies and won't be any better off for the next round with the virus.

Most everyone I knew when I worked in a grocery store basically never got sick, including my dad. He’s get sick once every 4-5 years maybe. People would call in sick, but it would be to miss a day.

Working in a grocery store, especially as a cashier, can be unpleasant to disgusting at times, especially when cash was a bit more common. I think you’re around everything all the time that your immune system tends to beef up a bit.

Conversely, the kids are getting hammered in winter time the last few years after covid after not getting sick between 2020-mid 2021.

I’m not so sure that humans evolved to avoid illness, despite how unpleasant it is.

This comment is an indirect appeal to nature: protecting yourself from exposure to pathogens is better than low level exposure if your intention is to not fall ill. I've seen a number of ill-looking grocery store employees (coughing, sneezing, sniffling, the works) before, during and "after" COVID.

Wearing masks does not compromise one's immune system: it just shields you from exposure to respiratory bugs. Kids are getting hammered because people have relaxed on wearing masks, so they are now more exposed than before.

> A few years ago I thought personal masking didn't really matter.

I have always looked at Japan as a mixed bag of things that the entire planet will be doing in 10-100 years (yes, even sex bots and other forms of liberal individualism). I am so glad that at least parts of the west have caught onto the practice of masking up when sick, if there were ever a silver lining from the pandemic.

I'm still looking for a solution to the mask straps biting into my ears on planes, but a few hours of discomfort is still way better than being sick when I get to/back from my destination.

For flying; try cutting the elastic and then tie both sides together behind your head. May make it a bit more snug on your face (which helps prevent your glasses getting so fogged up) but no back of ear pain at least :}

Cut the elastic ear loops off of an old mask and tie it to the elastic on a new mask to bridge the gap between the new mask ear elastics (or use a piece of string) so the pressure is on the back of your head.

If you fly a lot, there are also very likely commercial solutions for this.

A well-fitting elastomeric respirator is comfortable and much cheaper than n95s in the long run, but it will get more looks in public. If you're the kind of person who cares about that, just use 3m Auras.

>I'm still looking for a solution to the mask straps biting into my ears on planes

Try getting a proper N95 instead of a flimsy ear-loop mask: https://www.amazon.com/3M-Aura-Particulate-Respirator-9205/d...

N-95 masks are rated to capture 50 um (micrometer).

COVID-19 is 10.5 um. Water droplet to carry them just a tad bit above.

Hydrostatic testing to get that 50um in N-95 mask were based on 8.0 pH Latex hydrostatic droplets.

COVID-19 best infection spread rate is at 5.8-6.2 pH (opposite spectrum of Latex's pH).

So, more will pass thru that mask unhindered.

Not really. Due to brownian motion and diffusion the mask will catch almost all particles anyway.

The mask is rated to capture 95% of airborne particles generally, but it’s efficiency doesn’t correlate to the spacing within the filter media.

Brownian motion gets impacted if ions repels (as well as attract) at molecular and atomic level. And like pH, it has ions depending on where across the pH spectrum.

Now if they would construct a hydrostatic test using 5.8 to 6.2 pH aerosolizer, then the data becomes more robust.

These numbers are suspect, and the conclusions are wrong. Filters don't work that way.

Pray, can you elucidate on your non-factual statements?

I have a smile that could sink a thousand ships so I consider wearing a mask to be a public service to the rest of you.

thank you for your service

> The thing I don't miss is that I got sick every single Winter. All it takes is one inconsiderate person to not cover their mouth and everyone is getting ill. And it happened all the time.

Give it a few years without exposure, and you will have very hard time if you have to get exposed again. I did 2 years for remote work with a single day with long exposure each week, after a few years with low exposure.

I then had a kid, it took at least 3 full years once it got to day care for my immunity to get trained back to normal. Middly sick at least 4 months total per year, strong fever and/or weakness 4-5 times per year.

I'm all for limited exposure to dangerous infections, but for the sake of everyone, we have to keep our immunity active to stay healthy, and this happens by getting sick times to times.

Nah, its just what happens when you have a kid. I was exposed all the time commuting to work on public transit. Once my kid got into preschool I was sick for months at a time.

It's hard to explain the near exponential increase in pathogen exposure when 20+ kids are in a room doing the least hygienic things imaginable for 4-8 hours a day.

I rode the subway every day for years and rarely got sick, but a few weeks of a kid in daycare and it was all coming at me at once.

The running joke among my doctor friends is that pediatricians are immune to disease. Sick like a dog for the first couple years but then they become bullet proof.

And everything, literally everything, is going straight in the mouth unless you tackle them to break up the play.

I think this is based on a misinterpretation of the hygiene hypothesis... exposure to germs helps when you're a child yourself but not after becoming an adult (AFAIA). This is supported by https://medical.mit.edu/covid-19-updates/2020/05/all-social-...

I understand I have no authority on the subject, but, aren't we well aware that immunity wears off at different rates depending on the strain ? A lot of sickness only affect the children, and once for their lifetime, but there is at least covid for we know the immunity wears off. Surely there are many others.

edit: I suspect the article only states that life long immunity does not wears off. I don't challenge that at all.

This isn't really as simple as a linear decrease in immunity though - certain tools that your immune system uses like antibodies decrease over time but other tools like T-cell responses are long lasting. Thinking of it in terms of an acute response where you're very strongly protected and a persistent response where you have a slower but still effective protection is a better model.

But don't parents getting sick at work and bringing it home to their kids help the kids get exposed?

Or do you think kids get enough exposure at school? (assuming schools don't keep going remote too)

Based on how consistently my niece has been sick since starting school this year, I'd say they get enough exposure at school.

That's one of those sciencey articles that is only technically correct within a specific context, otherwise why are elderly people advised to get the flu vaccine every year?

> Give it a few years without exposure

> we have to keep our immunity active to stay healthy, and this happens by getting sick times to times

Is going to the grocery store, out to dinner, having friends/family over not enough exposure? Genuinely curious about the science if you need to be around kids (directly or indirectly via co-workers) to build or maintain a "strong immune system".

If anything I'd expect the lack of activity to cause your immune system to be hyper-aware and you'd get less sick. Trade-off is allergies and autoimmune disease.

I mention the kid only because it was the the main change to sickness exposure. I suspect public transport and office work would have been enough.

Given what we could read about covid, exposure is a combination of length and probability of sharing air with sick people. Public transport is a short exposure with many people, evening with friend, long exposure, but less people. Kid: well for all the sickness they have bad immunity for, and the long length of exposure, you have good chances ti get something that you never had or have no immunity for anymore.

My experience is that I now use public transport every day and I have two kids, I get sick time to times, but much less than a few years ago.

>If anything I'd expect the lack of activity to cause your immune system to be hyper-aware and you'd get less sick

That's not really how it works afaik. The immune system can only respond quickly and effectively to the things it knows. If you spend 3 years outside society and you come back, your system will be 3 years behind on disease evolution. When you finally do get exposed, you'll have a much stronger immune response because it's an unknown threat.

Compare this to a immune system that has also never seen the latest variant, but has seen the one before -- it'll be much more effective at recognizing and fighting the threat early, and the person might not even notice they were exposed.

> The immune system can only respond quickly and effectively to the things it knows.

Is that true? I'm not sure. Another question is what does it mean to be "known". I'd get a cold or a flu every year. At what point has the virus mutated sufficiently so that I don't have an effective immune response? This is also a great point to get vaccines. Best of both worlds.

>At what point has the virus mutated sufficiently so that I don't have an effective immune response?

I don't think anybody really knows, this is an active area of research. What is known is that, the more similar a virus is to something you already had, the more likely your immune system is to be able to respond quickly enough that you don't show any symptoms and don't even realize you were exposed. And if you do show symptoms, it'll be more likely that they will be much milder than for somebody who wasn't exposed previously to something similar.

I went to work every day when my kids were small and taught roomsful of college students. I still got poisoned by my little vectors who were a magnet for every virus in the Metro DC area.

There is no scientific basis for this assumption (the idea that you rake in immunity "debt" by not getting sick, leading to worse symptoms /when/ you get sick).

It seems plausible that the immune system requires stressors to function well, and the absence of stressors may reduce immune system "strength". Selye's general adaptation syndrome seems applicable here as a first approximation. Muscles atrophy from disuse. Why not also immune systems?

"Immunology Is Where Intuition Goes to Die"

https://www.theatlantic.com/health/archive/2020/08/covid-19-...

The immune system is never dormant. It is constantly engaged. We don't live in a sterile environment, don't eat perfect sterile food, don't breathe perfect air, etc. There are multiple aspects to our immune system, and a lot of them are being stressed daily.

It's not "immunity debt" but rather that immunity for seasonal diseases is not permanent - you lose it if you don't use it, basically, with "refresh period" about the same length as the disease cycle.

I don't have citations handy, it's just something I've seen mentioned here and there some months ago, as a possible explanation why after 2 years of lockdowns, many more people seem to catch the common seasonal diseases.

Immune systems don't weaken from a lack of exposure. It's not a muscle that needs to be worked out. Besides which, your immune system is pretty much constantly at work with relatively benign foreign tissue regardless of whether you're wearing a mask or not.

Some things like the uptick in RSV can be explained by children being initially exposed to RSV a bit later than usual, but for your average adult that's not really relevant.

> The thing I don't miss is that I got sick every single Winter. All it takes is one inconsiderate person to not cover their mouth and everyone is getting ill. And it happened all the time.

When I visited Hong Kong in 2008 I was amazed by how many people wore masks (presumably because they were either feeling sick or were worried about getting sick). It's too bad that post-COVID masks have become associated with authoritarian government overreach in many parts of North America.

> COVID masks have become associated with authoritarian government overreach

I wonder why?

> The thing I don't miss is that I got sick every single Winter.

Everybody is always entitled to their values and preferences of course, but it's really hard to see how a chance of getting sick once a year is a worse outcome than a guarantee of missing out on normal society permanently, particularly when you can do everything about as perfectly as you possibly can and still get sick.

It's similar for me and I still get exposed to people in the non-work part of my life, quite a lot actually, I just don't get two crammed train cars full of people twice a day anymore. I'm not as healthy as during quarantine, but I'm mildly sick-ish right now and I used to get knocked out for a week or so around this time before wfh almost every year and be a lot sicker otherwise, so whatever I'm being exposed to right now my immune system seems to be able to handle. I had a few infections in spring and summer when everyone here finally came out of quarantine, so I guess the post-isolation shock is already behind me.

Besides, if "normal society" means miserable unpaid commutes and cold offices with bad cafeteria food and a lot less time and energy for the things in life that really matter, then I'm quite happy to miss out on that. I'm not living in some kind of self-imposed total isolation, if anything I'm more active outside work these days, and my whole life feels a lot healthier (and that sure helps too)

> All it takes is one inconsiderate person to not cover their mouth and everyone is getting ill. And it happened all the time.

It's really depressing that even with the pandemic, the ratio of people covering their mouth didn't seem to have increased at all.

Local businesses who buy/grow local, hire local, pay local taxes etc benefit the community in ways that Amazon cannot. Local business also support local events/charities/etc. I think there is a lot of long-term economic benefit in decentralization of money and power, apart from social benefits like increasing trust between citizens. Just my view.