What has happened to Alpha and Delta and co and will they come back?

[Siuan]

90% of cases now thought to be Omicron.
It seems to me that Omicron is very different from the Wuhan and all the other variants. I'm cautiously optimistic that it might be the turning point in the pandemic if it proves to be mild in all but the unvaccinated.

It might be a stupid question but I don't understand what happens to the old varients now that Omicron is dominant. Can anyone explain please?

A few weeks ago there were 40K+ cases of Delta. If Omicron hadn't turned up I imagine that would have continued. Are there still pockets of all the old varients? Could they surge back?

I don't know the answers but I'm curious about this too. Bump.

Same op.
I'm also wondering if the virus can turn nasty again?
I'm cautiously hopeful that this is the break Through we have been waiting for.

Same thing that will happen to Omicron.

When they stop talking about it incessantly on the news it goes away and everyone forgets about it.

They just die out. Older variants will still be spreading but some of the people who would have got them will now catch Omicron and then be resistant, so they won't catch or spread Delta etc. Omicron wipes the board and older variants can't spread and they die out.

Viruses usually evolve to be milder. Think about it - with a mild virus you're more likely to go out and about and spread it. A severe virus will keep you home. Milder viruses are easier to spread around and cancel out the more severe strains. Covid has a particular problem with being asymptomatic in many people, which helped it to spread.

You can get a phone game called plague inc where you're in charge of a virus that is trying to take over the world - it will give you a rough idea of what's involved!

What I understand from the media coverage is that delta took over from alpha because it was more contagious, and if you have had one that gives immunity to the other. So as more and more people got delta, alpha couldn't spread to them so alpha became less and less common, though I suspect there will still be pockets of it in some places. However omicron and delta don't seem to convey as much immunity to each other so delta isn't suppressed as much.

I don't believe Alpha exists any more "in the wild"... it's been out-competed in the evolutionary virus race and will no more return than the dinosaurs will. As for Delta, it's still there. It remains to be seen whether it co-exists or is fully wiped out by Omicron.

Omicron is 'fitter' and is currently displacing Delta. The older variants were in turn displaced by later fitter variations of the virus, they won't return. Of course this is an evolving situation and another variant that is fitter than Omicron may well come along. That doesn't mean it will be worse, though.

'Fitness' is just the term used when one variant out-competes the previous one, could be any number of factors that make it fitter (for example, may bind more strongly to receptors, may replicate a little faster, etc).

I read that Omicron wasn't actually a variant of Covid 19 but from a 2017 Covid outbreak.

Can't remember where I saw that now, the whole thing is so confusing.

Omicron is actually closer to Alpha, here's a paper on that:

onlinelibrary.wiley.com/doi/10.1002/jmv.27515

@stayathomegardener

I read that Omicron wasn't actually a variant of Covid 19 but from a 2017 Covid outbreak. Can't remember where I saw that now, the whole thing is so confusing.

This makes no sense at all. There was no Covid outbreak in 2017! Also, if Omicron is so transmissible, how come it infected hardly anyone for four years, and then suddenly infects people at crazy rates? It's just absurd... It sounds like you got this from a conspiracy site.

Ds had covid recently. I thought if it was delta, he might be able to get omicron or vice versa, as they are so different.
Is he pretty safe for a few weeks/months, then?

They just die out. Older variants will still be spreading but some of the people who would have got them will now catch Omicron and then be resistant, so they won't catch or spread Delta etc. Omicron wipes the board and older variants can't spread and they die out

This doesn't happen with flu viruses though? Each year a different one seems to be prevalent, hence the slightly different flu vaccine every year.

Delta does seem to give some immunity to Omicron, that's why Omicron has been mild in South Africa. They have a low vaccine rate but very high levels of previous infections. But as far as I can tell the immunity doesn't extend to infection, just against severe illness.

I can't remember where I read it now, but I'm sure I saw one possibility being suggested for why Omicron was so mild in South Africa was that they were hit badly by Beta last year. Beta seemed to evade vaccines more than Alpha and Delta so was similar to Omicron in that respect. Beta never really took off here though as Delta reached us at a similar time and was more transmissable.

There is an initial study out suggesting Omicron infection helps to protect against Delta. Early days to draw definite conclusions though.
mobile.twitter.com/sailorrooscout/status/1475827859407228934

Had delta in August and despite numerous contacts with omicron(?) people in the last month, I m still negative.

@treeflowercat

I don't believe Alpha exists any more "in the wild"... it's been out-competed in the evolutionary virus race and will no more return than the dinosaurs will. As for Delta, it's still there. It remains to be seen whether it co-exists or is fully wiped out by Omicron.

I thought Omicron was a mutation of an Alpha case (patient zero was immunosuppressive and had Alpha in their system long term)?

@stayathomegardener

I read that Omicron wasn't actually a variant of Covid 19 but from a 2017 Covid outbreak. Can't remember where I saw that now, the whole thing is so confusing.

There is no Covid from 2017. Omicron however, is not descended directly from Aplha or Delta, but from the original Covid-19 that we had at the end of 2019/start of 2020.

Well that makes more sense @StrawberrySquash

This doesn't happen with flu viruses though? Each year a different one seems to be prevalent, hence the slightly different flu vaccine every year

The scientist take an educated guess on the flu vaccine depending of science data around the world and plan accordingly it’s not a new virus it’s a mutated virus.

Suggestions are that Omicrom give immunity against Delta hence the spread of Omicrom and reduction in Delta

This doesn't happen with flu viruses though? Each year a different one seems to be prevalent, hence the slightly different flu vaccine every year.

Yes - a different flu virus is prevalent each year because the rest have essentially been outcompeted - same as covid.

It's a bit like a family tree

Move aside Delta - there's a new sheriff in town.