Temperature likely has no effect on the transmission of Covid-19 | Hacker News Reader

Temperature likely has no effect on the transmission of Covid-19

aip.scitation.org

33 pointsrespinal23 comments

I think they could be measuring the wrong thing. While it may be true that the air temperature doesn't change the biology of the virus, air temperature definitely changes human behavior (what activities we do and where we do them).

On the one hand, this is a useful thing to know.

On the other hand, it does seem almost guaranteed to be misinterpreted by most news sources.

Is it known whether transmission of the flu (which is definitely seasonal) is affected by temperature in the way this study covers?

As far as I can tell there’s no great consensus, but the 3 popular theories seem to be 1) more time indoors, 2) less sunlight thus less vitamin D, and 3) the virus itself transmits better in cold air.

it is definitely affected in another way - temperature and humidity do affect the droplets which carry the virus. If i remember correctly the longest droplets lifetime is around the flu seasons.

>though protein denaturing occurred at 51 °C

no need for masks in sauna :)

Also immune system response, and so probably severity

I think that they are measuring the correct thing. It’s useful to know how temperature affects the molecular structure of the virus. From a quick glance at the study, they aren’t trying to determine how weather is going to affectHuman behavior, but I’m sure it will be misunderstood this way.

Do the molecular structure of spike protein of any seasonal flue change based on temperature?

As I understand it, we don't fully understand why seasonal flu is seasonal. The popular suspects are: A change in behavior of people. The decline in the amount of ultraviolet radiation (that damage or kills the virus). That drier air lowers the body defense against respiratory virus infections. That decomposition rate of viruses occur slower in lower temperatures. And finally the lover levels of vitamin D in colder climates.

Does this study provide any evidence in regard to any of those theories?

Also, it lets you know whether you could change the temperature inside grocery stores and the like to minimize transmission

Temperature doesn't meaningfully affect the spike protein. Neat.

Temperature changes droplet dessication, so heated air that is not humidified will generate more aerosols, increasing the transmissibility of the disease.

Pretty misleading title, actually.

Study: "Effect of ambient temperature on respiratory tract cells exposed to SARS-CoV-2 viral mimicking nanospheres - an experimental study". Accessible at: https://doi.org/10.1116/6.0000743

The title of the article describing this research paper is very misleading.

Here's the primary conclusion of the paper:

"Moreover, the ambient temperature changes from 4 to 40 °C had no effect on S-RBD-ACE-2 ligand-receptor binding and minimal effect on the S-RBD protein structure (up to 40 °C), though protein denaturing occurred at 51 °C. Our results suggest that ambient temperatures from 4 to 40 °C have little effect on the SARS-CoV-2-ACE-2 interaction in agreement with the infection data currently reported."

Where I'm from, the temperature regularly drops to -25 °C in the winter, so this study does not generalize well. In fact, the final conclusion is so weak, it may as well be discarded: "...results suggest...temperatures...have little effect...on the...interaction".

However, this study does prove that saunas and steam rooms kill SARS-CoV-2, as "protein denaturing occurred at 51 °C", which is well below the average temperature reached in a sauna.

I was under the impression that the mechanism for climate affecting transmission was that virus particles stay alive and aloft longer in colder, drier weather, and not related to receptor binding dynamics. It's obviously nice to know that binding dynamics don't seem to change with temperature, but the way the headline is presented seems to make a very different claim than the far more specific, and imo, less practically relevant claim that it actually makes.

How about UV light and humidity?

DHS made a tool months ago allowing you to play with temperature, humidity, and UV light: https://www.dhs.gov/science-and-technology/sars-airborne-cal...

UV light is the most significant factor of these three by far.

Considering this tool, I'm not sure what new contribution the referenced study is making.

How many degrees is the killer temperature for covid?

I have read that hot water does not kill it, but have not found what is upper temperature of breaking protein bonds.

Although, it has temperature resistivity - it is not resistant to alcohol and detergents ...

The authors say the SARS-CoV-2 proteins "denature" (essentially falling apart) at 51C.

Do you recall how hot that "hot" water was?

Let me try to find the article and make an update with link. This is the one does not says anything about temp. https://covid19.nj.gov/faqs/coronavirus-information/slowing-...

Additionally I am interested what is the least concentration of alcohol or soap that would kill it?

Sigh. The garbage statements as in your link is a major reason why people think SARS-CoV-2 doesn't exist, as boiling water is commonly known to sterilize fabrics by killing bacteria and viruses. Why we can't speak with more precision, I don't know.

The least concentration, I don't know, but here's information on a variety of disinfectants: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7190516/table/t...

I'm surprised they didn't include OTS isopropyl alcohol of soap in this analysis.

Here's a good one: https://journals.sagepub.com/doi/pdf/10.1177/002203452092058...

"All surfaces that may be touched by the patients should be disinfected with sodium hypochlorite 0.1% or 70% isopropyl alcohol."

Hope this helps somewhat.

Interesting link between hand eczema and overzealous hand hygiene: https://www.jaad.org/article/S0190-9622(20)30660-5/pdf

Thanks for the links. When I searched for the info, I hopped that those .gov and nhs ones will be most credible. :/

What I am finding very interesting from disinfectants list is number 14.

In China it's winter and all the major hotspots are in the north (ie. colder regions): Hebei, Heilongjiang, Jilin, Liaoning, Xinjiang, etc.

is it possible that while human typical temperatures might not effect covid specifically, but DO effect other flu's and colds... and because THOSE spread easier then that increases the covid vector?

What absolutely guarantees transmission of covid19 is contact between people, interaction in the same spaces.

Should probably have minimized that, like a year ago.

But I guess they are going to try to find every other loophole until they come back around to "hey if people don't interact, they can't transmit the virus".

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