Omicron cases are mild so far | Hacker News Reader

Omicron cases are mild so far

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15 pointsmpweiher32 comments

This could be the "endemic version" of COVID that we've been looking for. Particularly if it really is so much more infectious than the other variants and so manages to displace them.

Could be. We've been waiting/hoping for something endemic but mild.

But there's no particular reason COVID would need to get any more mild than Delta.

> But there's no particular reason COVID would need to get any more mild than Delta.

Can you elaborate?

Viruses evolve to become more mild because very sick or dead hosts are bad spreaders.

Covid has a long incubation period before symptom onset (when somebody notices and isolates or becomes bed-bound). So Covid, especially Delta, spreads well for days, whether or not ultimately symptoms are mild or ultimately it causes death.

Therefore a mild version of Delta wouldn't necessarily outcompete a non-mild version of Delta, all other things being equal.

> Viruses evolve to become more mild because very sick or dead hosts are bad spreaders.

This need not be true. There are many ways a virus could spread more while simultaneously making people sicker and causing more death. For example, a strain evolving to cause people to be contagious and spread for twice as long as now and then killing everyone could very well spread more than it does now.

Which variants survive in the wild is natural selection. Too deadly and it kills the host before spreading. The viruses that spread the most are the ones least noticed.

Example: common cold viruses. They're essentially always there and only make you sick when your immune system weakens a bit, and goes away quickly as well.

Speak for yourself, my son has brought home some gnarly stuff over the past few years lol. About 3 years ago I was sick for like a month and felt not great for 2 months haha.

Could have been a flu in that case. Colds are usually pretty benign though.

Diseases don't really need to become mild if they can spread sufficiently fast and aren't killing their host before they can so.

SARS-CoV-2 is already endemic, and causes mild common cold symptoms for the vast majority of youths. This is exactly the same as the other four endemic human coronaviruses. Most of us get infected with those when we're young and the resulting immunity protects us when we're older.

Why would that be something to look forward to? can't it still mutate to cause harm?

Variants can have mixed qualities. For example, one could be suitable for maximum spreading yet also have a weakness that makes it easier to treat as an illness

My understanding is that diseases tend to naturally select to be more contagious but less harmful. The more contagious more harmful mutations tend to die out because they incapacitate the host before maximally spreading vs. less harmful mutations. Not to say it's not possible for a more harmful mutation to spread widely, just that it's not the expected evolution.

In a vacuum this isn't true: diseases will select to be more transmissible, that can mean less deadly, but not always, think HIV. If the incubation time is long enough before death, then it could not matter. So, you could imagine a nightmare scenario where some disease selects to have a longer incubation time while still transmitting, but then causes more severe disease down the road.

However, because we have vaccines, I do think ultimately you're right. If it turns out that omicron (or another variant) is basically a cold but also evades current vaccines, I think society will 'allow' it to become endemic.

On your first paragraph, I agree entirely. Regarding the second: with the vaccines only preventing or reducing severe symptoms without seeming to reduce viral load, they slow the progress of respiratory viruses toward low-impact variants. The mechanism of this is that sick people stay home and consequently, if you are a viral variant that makes people sick, you get outcompeted by variants that allow people to go about their days and keep spreading.

In this sense, low vaccination rates of Africa may be just what we needed.

> In a vacuum this isn't true: diseases will select to be more transmissible, that can mean less deadly, but not always, think HIV.

Is there any evidence of diseases that have selected to be less deadly, aside from by killing all of its especially vulnerable hosts? As far as I can tell, this is naive optimism: the selection pressure for not killing your host is irrelevant if they're only going to be infected for a week or two anyway, and basically every mutation that's going to increase transmissibility is likely to be negative (increased viral load in infectious agents, immune escape, etc.).

>Is there any evidence of diseases that have selected to be less deadly..

It sounds like you're asking for specific examples of pandemics that didn't happen because they weren't detrimental enough to endanger people. That category of respiratory viruses is often broadly described as "the common cold."

No, I'm asking for specific examples of deadly viruses that have become less deadly over time. Like, take smallpox as an example. It's probably been endemic in humans for thousands of years: what's happened to its mortality rate? It's still at 30%, and the reason it's so low is due to human adaptation: the native Americans were virtually wiped out by it.

> It's probably been endemic in humans

It probably was endemic, as it was declared eradicated in 1979 by an effective vaccination campaign.

More importantly, though, smallpox, as a complex DNA virus, had far fewer viable mutations. That fact, along with an apparent lack of non-human reservoirs, is probably why it could be eradicated.

This article claims that was the case for H1N1, as well as the "common cold".

https://www.gavi.org/vaccineswork/will-covid-19-evolve-be-mo...

HIV and coronaviruses are completely different and can't be compared.

HIV is clinically a mild virus and doesn't cause any severe symptoms by itself. It is only when HIV becomes AIDS that it is dangerous, but then again, the symptoms are not caused by HIV/AIDS itself, but by the lack of immune cells caused by AIDS. You could have HIV forever and not even notice it if you were in a vacuum as you say :)

We can't know how severe Omicron will be, but let's hope it just becomes a cold. As OP said, the most enduring parasites (viruses are categorically parasites), are the ones that don't kill their hosts. This is not only true for viruses, but all kinds of parasites.

That’s not actually true. Many AIDS patients will die of cancer due to a lack of immune system suppressing those common occurring cancers.

Cancer is an additional disease, and not caused by AIDS itself.

It could happen regardless of external factors, so I guess my "vacuum" analogy wasn't perfect. All I mean is that HIV/AIDS itself doesn't kill you by itself.

Not quite. The body would natural develop several types of cancer without an immune system to suppress them. People with AIDS will have short lives even without exposure to any external diseases.

Yes, it could, but potentially you reach a point where there is little or no interest in vaccination. In that case the harmful mutations are self-defeating because they get stuck at dead-end homes with their hosts, who stay home from work.

In the highly vaccinated version of the story, vaccinated people are mostly unaffected by the severe effects, so they go about their lives and, if they happen to be the ones with the harmful mutations, they give those variants a fighting chance to spread. It would be different if the vaccines reduced viral load, but the limited studies available don't seem to point in that direction.

This is not true - this comes from a misquoted south African doctor. The variant is still dangerous.

Pfizer up 25% MoM: https://www.google.com/finance/quote/PFE:NYSE?window=1M

Moderna up 24% in the last 5 days: https://www.google.com/finance/quote/MRNA:NASDAQ?window=5D

New variants are great for business!

Pfizer has also announced they can get a new vaccine out for a new strain in 100 days (assuming regulators approve.)

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