The Omicron variant

Lumen · 07-12-2021 11:57pm

@lbj666 wrote

Early estimates of the r0 in the UK is over 3

Source? That sounds way off. Are you sure you're not quoting a tweet with a typo?

ACitizenErased · 08-12-2021 12:02am

https://www.boards.ie/discussion/comment/118287780#Comment_118287780

Weird how 50% of the vaccinated sample are only 12 days post dose 2. No info on intervals listed.

Is this a possible explanation for such a big difference between vaccination vs vaccination + infection ?

Mango321 · 08-12-2021 12:03am

https://www.boards.ie/discussion/comment/118287798#Comment_118287798

It's Rt, not R0.

Rt = in a specific time and place.

R0 = in a completely uninfected/unvaxxed population with no public health measures.

Mango321 · 08-12-2021 12:10am

Several sources agree that Rt for Omicron in the UK is currently around 3 (i.e. 1 person infects an average of 3).

(If Rt is 1, cases plateau.)

https://twitter.com/AlastairGrant4/status/1468151959957950466

Wolf359f · 08-12-2021 12:10am

https://www.boards.ie/discussion/comment/118287849#Comment_118287849

The vaccinated only was 12 days post dose, vaccinated and infected was twice that.

Guess if you look at antibody levels from people after their second dose, you could see if there's a significant difference between day 12 and day 24 etc...

Be nice to see if other countries do a similar test, just to confirm it etc... Still early days.

lbj666 · 08-12-2021 12:11am

https://www.boards.ie/discussion/comment/118287813#Comment_118287813

You'll see the source post , same source say that's double every 3 days.

amandstu · 08-12-2021 12:46am

https://www.boards.ie/discussion/comment/118287902#Comment_118287902

I heard them say double every 2 days (BBC I think)

lbj666 · 08-12-2021 12:53am

https://twitter.com/AlastairGrant4/status/1468183620162670595?s=20

nocoverart · 08-12-2021 2:41am

My head hurts just reading the last few pages about this sh1t! Don’t know how some posters on here post frequently everyday.

amandstu · 08-12-2021 3:26am

My head hurts too.

"Scientists believe previous infection, followed by vaccination or a booster, is likely to increase the neutralisation level and will probably protect people against severe disease"

https://www.bbc.com/news/world-59573037

Are they really suggesting that the vaccines should work well against Omicron provided you have already been infected ,but not if you have only had the vaccine?

Lumen · 08-12-2021 6:38am

https://www.boards.ie/discussion/comment/118288319#Comment_118288319

Yes. That's the case for all variants. Infection is like a really unsafe, unreliable vaccine (immune response from infection is much more variable than from vaccination).

The safer way to build immunity is with another dose of vaccine, although if Omicron isn't more pathogenic on a case by case basis then infection after vaccination may be tolerable for many.

There's obviously the philosophical issue of whether there is any sense in getting hit by the thing you want protection from to get protection from being hit, but that's one for the "natural immunity" enthusiasts.

deholleboom · 08-12-2021 9:44am

Every model and equation is built upon presumptions and assumptions.

In the end we can only do that with more certainty in hindsight. It's a bit like the climate change models. So, for Omicron, as it stands, no matter what the R number is it is anyone's guess how to equate infections with hospitalizations and deaths. We know what it is with Delta but we can only go on real life data in regards to Omicron, ie numbers into hospitals because of symptoms, the hospital duration, the severity and deaths. It looks positive at the moment. After a month in South Africa. Is there any real reason to think it will be significantly different in other countries? In other words, has all that guesswork any substance? I will stay positive until someone can show me the statistics. And no models please....

deholleboom · 08-12-2021 9:54am

The current problem w trying to establish the R number is that we need sequencing to establish the value and you can only do that with a percentage of cases. As a lot of mild cases will fly below the radar the level of uncertainty is high. You simple cannot do a proper equation.

But people want answers to questions so they will be provided, no matter how uncertain the variables. C'est la vie..

Mango321 · 08-12-2021 10:04am

https://www.boards.ie/discussion/comment/118288645#Comment_118288645

The UK Omicron Rt/R estimates are from S-gene target failure (from around 50% of PCR tests).

They're not based on whole genome sequencing.

deholleboom · 08-12-2021 10:15am

https://www.boards.ie/discussion/comment/118288684#Comment_118288684

Thanks. In my eyes that is even worse. Estimates of an uncertain variable in relation to...etc etc.

deholleboom · 08-12-2021 10:37am

Wasnt it Mencken who said: "predictions are hard to make, especially about the future". I always thought that was very funny but in fact we do precisely that w the R number even in hindsight..

deholleboom · 08-12-2021 10:39am

https://www.boards.ie/discussion/comment/118288821#Comment_118288821

Though i would call them estimates..

timmyntc · 08-12-2021 10:52am

https://www.boards.ie/discussion/comment/118287668#Comment_118287668

Why would a 3rd dose do the same?

"hybrid immunity" makes sense - its largely better than just 2x pfizer because natural immunity from exposure has a wider degree of antibodies which bind to various parts of the virus that are not spike protein, whereas vaccines only induce antibodies to spike protein.

Is there any explanation anywhere as to why they think a 3rd dose of the same will improve things?

Lumen · 08-12-2021 11:01am

https://www.boards.ie/discussion/comment/118288888#Comment_118288888

Is there any explanation anywhere as to why they think a 3rd dose of the same will improve things?

It's speculative at this stage, but...

Even if the Wuhan variant antibodies generated by the booster are not specific, their sheer number (at least in the first couple of months after boosting) may overwhelm an Omicron infection.
The other components of the immune system are less affected by spike protein variations than antibodies.

timmyntc · 08-12-2021 11:16am

https://www.boards.ie/discussion/comment/118288939#Comment_118288939

I get that - but based on the difference in neutralising antibody affinity between 2x Pfizer and 2x Pfizer + infection in that previous study.. I guess its too early to tell really.

The infected individuals had infections with the original strain back in summer of 2020, so unless them getting 2x pfizer after that gave much higher antibody levels than any 2x pfizer participant could explain it.. I don't know.

We'd have to see unvaccinated & recovered serum antibodies against omicron too to compare and know for sure

08-12-2021 11:21am

https://www.boards.ie/discussion/comment/118288888#Comment_118288888

Increased Affinity maturation. Repeat exposures (either through vaxx or infection) don't just increase antibodies but increase their breadth and affinity for mutations in the virus.

https://en.wikipedia.org/wiki/Affinity_maturation

JTMan · 08-12-2021 11:30am

https://twitter.com/BallouxFrancois/status/1468493362688925700?t=Xl7ClhMvSZC5l0eCE7BZyA&s=19

Interesting counter view.

Lumen · 08-12-2021 11:30am

https://www.boards.ie/discussion/comment/118289018#Comment_118289018

Well crudely, 2 + 1 > 2 and 1 + 2 > 2...

The thing about infections is that they're not all equal in terms of immunity acquired. When immunologists talk about effects of vaccines vs infection, they emphasise the consistency of vaccination responses. Whereas with infection you might just get a mild dose and not develop much immunity.

One might argue (and I'm disappearing further into areas I don't understand) that people who have a mild dose have proven that their immune systems can cope and therefore don't need vaccination or boosting, but that assumes that the mildness is solely determined by immune fitness, rather than viral load or variant...variations. Nonetheless, this is already accounted for in our booster programme which disqualifies people from receiving a booster within six months of known infection.

From a community spread/protecting the vulnerable perspective I can see an argument for letting it rip amongst the young and vaccinated (or, with hindsight, having done that since late summer) on the basis that it will confer a higer level of herd immunity against Omicron, the problem is the collateral damage caused by leaking infections to the vulnerable.

timmyntc · 08-12-2021 11:49am

https://www.boards.ie/discussion/comment/118289092#Comment_118289092

Crudely yes, but it equally could be a case that immunity from infection gives a wider range of antibody responses (from exposure to full virus, not just S protein) meaning that it's more robust against mutations in S protein.

I dont doubt that a 3rd exposure/dose will boost antibody numbers too, but will it boost nAbs affinity to same level we see with 2xPfizer + infection (against omicron)? Somehow I doubt it but we'll see.

On the "let it rip" scenario, I think that should be driven more by rate of hospitalisation and death, but regardless of what we do, with this kind of drop in neutralisation performance, omicron will likely reinfect most of the population at some stage. It's up to us how fast that is - which again will be dependent on the rate of severe disease.

corkie · 08-12-2021 11:50am

CONFIRMED GLOBAL CASES 1,752

UK 440 -Source

Denmark 398 -Source

South Africa 255 (~67,312) Source

United States 55 -Source

Zimbabwe 50 -Source

+ Another 7 countries with 30+ Cases.

This maybe the last report from BNONews, as they have cleared the counts from each country on the map.

So site usefulness has expired with the Increasing case count.

https://twitter.com/M_B_Petersen/status/1468237024939360273

Omicron reported in 57 countries - WHO

El_Duderino 09 · 08-12-2021 11:58am

https://www.boards.ie/discussion/comment/118281033#Comment_118281033

Be fair though, Thy have only confirmed a few thousand cases of Omicron and they have been mostly in the last week. You wouldn't expect people to die in a week. Doesn't death usually take 4-6 weeks from getting the disease?

They're also being much more sensible about travel with this variant than the last 2 variants of concern. Travel restrictions, quarantine and negative tests needed for travel are huge steps forward and are definitely contributing to containing this variant.

Dismissing it as hysteria because nobody has dies yet is silly and probably disingenuous.