[princearthur]

Covid was "special" in a lot of ways (though of course it wasn't a lab leak.) Flu pandemics can be extremely deadly, however:

- 'Long flu' is not a thing (it's actually possible but it's rare, mild and short)

- Our baseline immune competence would probably be much higher (even though neutralizing antibodies to H5N1 are low in the population.) This should be particularly true for people whose first flu as children was with Influenza A.

- Unlike Covid, no reason to suspect H5N1 will cause diabetes, heart disease, or various other kinds of permanent damage. It's probably also unlikely to cross the blood-brain barrier.

- There are various vaccine efforts already in the pipeline.

I wouldn't expect it to be like Covid in 2020 but maybe like in 2023, after it went from the 3rd leading cause of death to the 10th.

[yawpitch]

Feel the need to point out that before it made the evolutionary leap to ready human-to-human transmission there was no reason to suspect what would become SARS-CoV-2 of being capable of causing long-term effects either.

We have no real idea what a highly human-to-human infectious novel H5N1 variant would do in humans, long-term, precisely because we haven’t infected enough people with it to find out.

[princearthur]

This is true. However, we've had zoonotic spillovers since before the dawn of civilization, and the Covid pandemic stands out in modern times in the ways I listed.

There's no reason to suspect the next pandemic will stand out in the same ways, or as much in general, particularly if it's Influenza.

[yawpitch]

The 1917-1918 flu pandemic also stood out for the many novel short-term and long-term effects, most of which we are still learning about because records and data collection were so poor. Every new spillover is an opportunity to learn what can happen that was not captured in our very bad memory of such events, effectively none of which have been rigorously recorded until the mid-20th century.

There is, in other words, no reason to suspect any particular outcome. Given how poorly we handled the still-ongoing SARS-CoV-2 pandemic there is zero reason for optimism.

[avazhi]

The scariest thing about COVID wasn’t diabetes or heart disease but the brain damage (microhemorrhages) and in particular the dementia-associated lesions it appears to cause in long-COVID patients.

[1attice]

Oddly, back in my prehistory (2005 to be precise,) I did a PhD-level internship at a hospital preparing for a possible H5N1 outbreak. This was based on the then-recent experience of what is now known as SARS-CoV-1.

The information we had at the time indicated that H5N1 could result in multiple organ failure. It's been literally two decades (!) and I couldn't tell you the specifics, but yes, H5N1 was deemed to be possibly 'special' in some way.

I'd link you to some resources about this, but your googling's as good as mine, and my information is indeed twenty years out of date.

All the same, as tempting as it is to reasssure oneself with rules of thumb, it's even better to reassure (or perhaps unsettle) oneself with genuine facts, and there's no shortage of these regarding H5N1. I know with certainty that we've been worried about it for decades :)

[bsder]

> 'Long flu' is not a thing (it's actually possible but it's rare, mild and short)

That is not at all demonstrated scientifically.

"Long Covid" took quite a while to be demonstrated and we were monitoring everything like a hawk. "Long flu" has no such monitoring.

As soon as we had the tools and started looking for correlations, the collateral damage that viruses do pops up (HPV and cancer; Epstein-Barr and MS; Herpes and dementia).

Given that, the Bayesian prior favors "Long Flu exists and we just haven't paid attention" rather than "Long Flu doesn't exist."

My suspicion is that we're going to find more and more of these correlations as our medical ability to deal with viruses improves.

[princearthur]

> "Long Covid" took quite a while to be demonstrated and we were monitoring everything like a hawk. "Long flu" has no such monitoring.

It wasn't demonstrated because of the monitoring. It was demonstrated by the droves of desperate patients who kept banging on the clinics' doors and wouldn't take no for an answer. Claiming that 'long flu' is the same thing is (IMO) just a different variety of Covid denialism.