Per CDC Data the COVID-19 Death Rate Peaked in the US in April 2020 – There are More Pneumonia Deaths Than COVID-19 Deaths in 2020

Gateway Pundit ^ | 08/18/2020 | Joe Hoft

[2aProtectsTheRest]

Right here (for one): https://www.ncbi.nlm.nih.gov/books/NBK143281/

"the term droplet is often taken to refer to droplets >5 um in diameter that fall rapidly to the ground under gravity, and therefore are transmitted only over a limited distance (e.g. >1 m). In contrast, the term droplet nuclei refers to droplets <5 um in diameter that can remain suspended in air for significant periods of time, allowing them to be transmitted over distances >1 m"

There is an open question on whether the capsid for SARS-CoV-2 can survive at all within aerosols. Most studies to date have said probably not. Some recent studies (primarily based on laboratory work using a nebulizer) have suggested it may be possible. But to my knowledge, there has been no documented case of an actual transmission via aerosol. And all known guidance states that respiratory droplets remain the primary transmission vector for SARS-CoV-2. Reduce the volume and range of respiratory droplets (>5-10um in size), reduce the risk of SARS-CoV-2 transmission.

It's not a matter of whether you exhale or inhale aerosols. It's a matter of whether SARS-CoV-2's capsid can survive within aerosols long enough for the virus to remain infectious in the real world. So far, while that theoretical possibility has been shown (just as it has with fomites), nobody has been able to demonstrate that it's actually resulting in transmission (just like with fomites).

[Svartalfiar]

Right here (for one): https://www.ncbi.nlm.nih.gov/books/NBK143281/
"the term droplet is often taken to refer to droplets >5 um in diameter that fall rapidly to the ground under gravity, and therefore are transmitted only over a limited distance (e.g. >1 m). In contrast, the term droplet nuclei refers to droplets <5 um in diameter that can remain suspended in air for significant periods of time, allowing them to be transmitted over distances >1 m"

There is an open question on whether the capsid for SARS-CoV-2 can survive at all within aerosols. Most studies to date have said probably not. Some recent studies (primarily based on laboratory work using a nebulizer) have suggested it may be possible. But to my knowledge, there has been no documented case of an actual transmission via aerosol. And all known guidance states that respiratory droplets remain the primary transmission vector for SARS-CoV-2. Reduce the volume and range of respiratory droplets (>5-10um in size), reduce the risk of SARS-CoV-2 transmission.

It's not a matter of whether you exhale or inhale aerosols. It's a matter of whether SARS-CoV-2's capsid can survive within aerosols long enough for the virus to remain infectious in the real world. So far, while that theoretical possibility has been shown (just as it has with fomites), nobody has been able to demonstrate that it's actually resulting in transmission (just like with fomites).

Sure, "droplets" are over a certain size, but the majority of what you breathe out is not droplets, aside from coughing/sneezing.

As for transmission, I don't think there's really been that much confirmed cases of any mode, it's not something I've really seen in the news at all. But, from that same post I linked to above, the big study I've seen says aerosols certainly do promote live viri.

This website, NE Journal of Medicine, has a study on viral viability. Here's the quick points:

We evaluated the stability of SARS-CoV-2 and SARS-CoV-1 in aerosols and on various surfaces and estimated their decay rates using a Bayesian regression model
...
The inoculum resulted in cycle-threshold values between 20 and 22, similar to those observed in samples obtained from the upper and lower respiratory tract in humans.
...
SARS-CoV-2 remained viable in aerosols throughout the duration of our experiment (3 hours), with a reduction in infectious titer from 10^3.5 to 10^2.7 TCID50 per liter of air.

So I'm reading this as they started with a dosage of aerosols similar to what a person would breathe out, I have no idea on how many breaths worth of sample they did. TCID50 is "50% tissue-culture infectious dose", which sounds like it's a sufficient quantity of viri to cause an infection to start in their culture sample 50% of the time. Their aerosol test only ran for three hours (?), and it went from 3000x the infectious dose, down to 500x the infectious dose. This is PER LITER OF AIR, and for reference, a 10'x10' room with 8' ceilings has 22,000 liters of air. So, those numbers are a lot more dispersed, but also real life will have a lot more breathing (and possibly more people) to add continuing aerosol amounts. I believe they mention it's a logarithmic decrease, so as your number gets smaller, it gets smaller slower (could be days+ to get below the 1x TCID50), but you also have less chance of walking into it. And, I assume this study looked at a closed-air system, so your house/grocery with running HVAC/windows/open doors will likely cause those to get filtered/pushed out somewhat quicker.

[2aProtectsTheRest]

Sorry it took a while to respond, I had some family things happening the past couple days that took me away from these fun discussions.

I saw that study and it’s really interesting, but there’s a couple points to be made there. First, the World Health Organization pointed out (https://www.who.int/news-room/commentaries/detail/transmission-of-sars-cov-2-implications-for-infection-prevention-precautions) that this study used a high-powered nebulizer to generate their aerosols, which works significantly differently from humans. They also examined multiple other studies discussing the potential for aerosolized transmission, but detailed examination of both healthcare facility transmission patterns and crowded indoor public place outbreaks have shown no conclusive instances of actual transmission via aerosols. Every single case to date is explainable via respiratory droplet transmission.

Still, the possibility is acknowledged by them and others. The research from around the world continues to support transmission primarily by respiratory droplets.

Another aspect to consider is the basic reproductive number for SARS-CoV-2 (recent estimates put it as likely between 2.2 - 3.8). If you look through the R0 for various diseases, you find they generally fit into rough groupings based on their transmission modes. For viruses that readily infect via aerosols, you typically see an R0 in the 10-18+ range. For respiratory droplet transmission, you can reach up to around 7. For other things like bodily fluids (e.g. Ebola), you can hit up to around 2. Considering SARS-CoV-2’s R0 of 2.2-3.8, it is highly unlikely that aerosolized transmission makes up many (if any) of the actual real world transmission for it. Otherwise, it would be - by far - the worst performing spreader for an aerosolized virus that I could find any documentation on.

So sure, it’s at least theoretically possible there are some cases occurring due to aerosolized SARS-CoV-2, just like with fomites. But it’s highly unlikely that very many actual infections are taking place that way.

[Svartalfiar]

that this study used a high-powered nebulizer to generate their aerosols, which works significantly differently from humans.

True, but the point of the study is to look at aerosols specifically, so generating bigger droplets won't help with looking at aerosols. But yes, I do agree that the methodology is not exactly similar to human breathing.


Every single case to date is explainable via respiratory droplet transmission.

And, every case explainable as such, is also explainable by an aerosol vector. The two aren't mutually exclusive, they overlap a lot. Especially from a virus like this, where I've heard that it doesn't take a high viral load to initiate an infection.


Another aspect to consider is the basic reproductive number for SARS-CoV-2. If you look through the R0 for various diseases, you find they generally fit into rough groupings based on their transmission modes... Otherwise, it would be - by far - the worst performing spreader for an aerosolized virus that I could find any documentation on.

True, I haven't looked at that before. But, it's hard to really pin down these numbers during the course of spread, versus looking back at solid information. And, for the supposedly high number of asymptomatic carriers walking around, the R0 might be much higher than people calculate it to be. And of course, taking into account the entire US population ignores that the virus isn't even present at all in every community - R0 is difficult to truly calculate. If 16 people get infected, that could be an R0 of eight - only two people were the source infection for all of them. Or, an R0 of two, as each person infects two others til you hit those 16 people.

And a big indicator towards aerosols and not droplets, is the relatively large spreads in several States in these US where masks were heavily required - stopping droplets is the one thing these masks are actually pretty good at. but aerosols, not so much.