Viral load, is what this typically refers to. Akin to an allergic person seeing one cat versus a room full of them.

And, of course, for some people with allergies, contact where a cat has been is enough. ;)

So... Complicated.

Edit: was corrected down thread that this is infection dose, not viral load.

There’s a very weak association between viral load and symptoms once you’re infected.

But that is what the thread was talking about, right?

Would be nice to see studies. My intuition is that it is weak. But my intuition doesn't count for much here.

Is it? I read the original comment as saying there were significantly different symptoms based on the transmission method. Even assuming that the transmission method results in a significantly different viral load, that's not enough to explain differing symptoms since there's not a whole lot of observable difference between cases with different severities[1,2]. There are some studies that show a relationship, but nothing strong enough to explain a dramatic difference.

If it's true that the transmission method makes a big difference, it's more likely due to some other reason. E.g. maybe mild strains spread more easily in the air (although as far as I know there's no evidence that's true.)

[1] https://arxiv.org/ftp/arxiv/papers/2003/2003.09320.pdf

Page 3. "We did not observe significantly different viral loads in nasal swabs between symptomatic and asymptomatic."

[2] https://www.medrxiv.org/content/10.1101/2020.03.15.20036707v...

Page 4. "There was no obvious difference in viral loads across sex, age groups and disease severity"

Fair. My entry to this thread should have begun with a question mark. I thought the point of different transmission methods, as frames, was referring to potential differences in viral load.

Rereading your first comment, I think you might be thinking of infection dose. Viral load is the amount of virus present in a patient. Infection dose is the amount you're exposed to.

So, I was indeed mixing those up. I think most of the following points stand?

There's not much evidence that infection dose matters in terms of case severity either, other than you're just less likely to be infected in the first place.

Perhaps different amount of viral load