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Omicron news

There are more known unknowns that we know about than we know about the unknowns of which we don't know. Someone once said.
 
It is though perhaps 30 percent less likely to kill those who opt for "natural immunity" over an effective vaccine ... :hmm:
 
Speaking of the word mild and perceptions, here is some context I would like to have seen far more prominently:

Instead we've had plenty of conflation between the intrinsic severity of Omicron and the effect of vaccines and boosters.


One important caveat to that is something that the report itself notes - that it doesn't consider the relative severity of the hospitalised cases. As we're seeing, it appears far fewer people are ending up in icu or on ventilators with omicron, and if you're attempting comparisons with previous strains, that's an important thing to factor in.
 
Yes I totally agree that the caveats are mounting, things are much messier and harder to unpick these days due in great part due to complicated immunity picture. But yes, some more specifics about the clinical details of Omicron will also firm up a bit over the next period.

Plus you know me and hospital data, I'm prone to draw attention to a chunk of it actually being people who were in hospital for other reasons and then caught it there, and in the vaccine era those infections should lead to a different balance of outcomes than it did in the early waves.

Without having to do proper scientific analysis, we'll be able to do things like comparing what happens in the USA this month to what happens in the UK this month, because their immunity wall is missing a lot of booster vaccine doses compared to ours, and I think their previous vaccine coverage was also less well aligned to hugely cover as great a portion of the most vulnerable (older) population than ours has been.
 
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Found a tweet on that theme which somewhat sets that scene, but there is a further complication with attempting that comparison because the USA was at a different stage of Delta wave compared to us when Omicron arrived. And unpicking that wont be so easy.

Seems safe to assume that 'what stage of the pandemic it feels like we are at right now' is not going to be the same in the USA compared to the UK.

 
Anecdata about severity
I've just been chatting with the person I caught original Wuhan covid from (spring 2020)
She works in care homes for a national chain of homes
In Spring, 2020 residents (in homes that had covid ) were succumbing and dying rapidly
Wuth omicron it is in nearly every home in the chain and very few people are dying from it
 
Found a tweet on that theme which somewhat sets that scene, but there is a further complication with attempting that comparison because the USA was at a different stage of Delta wave compared to us when Omicron arrived. And unpicking that wont be so easy.

Seems safe to assume that 'what stage of the pandemic it feels like we are at right now' is not going to be the same in the USA compared to the UK.


I'm a bit surprised by how small the red bits are in the last charts, in the England one. I thought the UK was about 70% vaccinated. Do those graphs indicate that nearly all of the 30% or so unvaccinated have already had the infection?
 
I'm a bit surprised by how small the red bits are in the last charts, in the England one. I thought the UK was about 70% vaccinated. Do those graphs indicate that nearly all of the 30% or so unvaccinated have already had the infection?
% of UK vaccinated depends on how many doses and whether all ages are included or only people over a certain age.

For example at the moment the UK dashboard vaccine stats now use population figures for everyone 12 and older. It used to be higher ages only but they changed it as they opened up vaccination to some younger ages.

Right now for population aged 12 and up the dashboard has UK figures of 90.2% for first dose, 82.7% for second dose, 60.6% for boosters. These figures will obviously drop if we included all younger children in the population figures, and those sorts of total population percentages are what some people prefer to use on twitter etc.

The other thing to keep in mind is that the chart in the tweet will not be 100% accurate, its almost certainly based on the data we get from blood donors, and they arent completely representative of the whole population. When they analyse those samples they have 2 different antibody tests, one that shows antibodies caused by vaccination and infection (Roche S), and one that only shows antibodies caused by infection (Roche N).

See pages 41 to 47 of this report for loads of details, charts etc:


Here is some of the text from that which is relevant. The blood donors are aged 17 and over.

Roche S seropositivity in blood donors has plateaued and is now over 96% across all age groups.

Seropositivity estimates for S antibody in blood donors are likely to be higher than would be expected in the general population and this probably reflects the fact that donors are more likely to be vaccinated. Seropositivity estimates for N antibody will underestimate the proportion of the population previously infected due to (i) blood donors are potentially less likely to be exposed to natural infection than age matched individuals in the general population (ii) waning of the N antibody response over time and (iii) recent observations from UKHSA surveillance data that N antibody levels are lower in individuals who acquire infection following 2 doses of vaccination. These lower N antibody responses in individuals with breakthrough infections (post-vaccination) compared to primary infection likely reflect the shorter and milder infections in these patients. Patients with breakthrough infections do have significant increases in S antibody levels consistent with boosting of their antibody levels.

One of the reasons this data indicates so much of the gap being plugged is that their data for people with antibodies caused by infection demonstrates that younger people, who are less liekly to be vaccinated, have had the highest levels of infection, especially once the Delta wave happened. But thats also considered to have been true right from the start of the pandemic, younger people were in harms way for all manner of reasons including having more social contacts, and a rather large proportion of the older population successfully hid from the virus in the first few waves. Although I suppose younger people are also more likely to generate higher antibody levels which show up for longer. Anyway here is one of the charts about that from the same report:

Screenshot 2022-01-07 at 03.00.jpg

Previously when this subject came up I disagreed with littlebabyjesus about the extent of assumptions we could make in regards how many unvaccinated people had not yet been infected either. Thats partly down to the limitations of the blood donor data as already discussed, I prefer to leave a bit more wiggle room in my assumptions about this. But given the scale of the Omicron wave, reality will already have moved to become closer now to what littlebabyjesus assumed about this weeks ago.

We might be able to further refine our sense of how many unvaccinated, previously uninfected people remain in the population by keeping an eye on data about the vaccine status of people who have been hospitalised or died over a recent period. Such data, which tends to cover a 4 week period, is a bit laggy and wont be covering a 'mostly Omicron' period yet, but I will fish the latest version of it out anyway at some point on Friday. Actually its in the same report I already mentioned, a few pages earlier. Although if we use it for that purpose, we'll be making an assumption that this is those peoples first infection, which isnt necessarily the case. And there are plenty of deaths of vaccinated people in it which demonstrate that the immunity wall has its limits, especially as people get older. It doesnt currently offer info about whether they had a booster either.
 
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On a highly related subject, I am sorry I've been so rude to people with certain views in the pandemic so far, but I really hope that the current situation helps a few more people understand why I get so frustrated about those views....

Even assuming the current intensive care numbers and deaths dont shoot up a lot from their relatively stable levels in this wave, we've still had enough hospitalisations to cause real problems to the system. And this is under circumstances where we've got a variant that is less severe than Delta, and a really large prior infection & vaccination wall. So I'm bound to declare that even when we are beyond the acute initial phases of the pandemic, when the virus was still new to our bodies, this virus is still looking like a shit to manage. The original version of herd immunity that some tried to sell us now looks especially stupid, not least because immunity from infection and transmission has proven elusive. We are going to need some combination of things settling down on the new variant front, even less severe disease consequences, more treatments that can be given at home early to reduce the chances of hospitalisation, vaccines that can do more to prevent infection and transmission, and perhaps some other stuff I'm forgetting to mention right now, along with an overall population immunity picture that is less conducive to large waves being able to happen, in order to at least avoid putting hideous pressure on our hospitals and those who work in them. On paper the rather large Omicron wave should get us closer to that situation, but given how tricky things have been despite much progress on many fronts I'm unwilling to express a huge amount of confidence about that at this moment.

Anyway the point is that even if we make it to the stage where its much more feasible to cope with the virus in future, how difficult things have still been in this wave, even with much less really severe disease potential, hopefully shines light on just how big the threat was in the past, the extent to which non-pharmaceutical measures were essential to even begin to stand a chance of coping in those early waves. Lets just hope that living with 'endemic' covid is several degrees less of a nightmare than the Omicron wave has been for hospitals. I still dont rule out the possibility that living with covid long term may require permanent changes to the nature and capacity of healthcare systems, especially surge capacity. Especially if flu bounces back and demonstrates an ability to have waves that can coincide with covid waves, which is something I'm not at all clear on at this point, I guess nobody is too sure about that until we see it happen, or not happen for a prolonged period.

With that in mind I actually sort of hope that the immunity wall the data mentioned earlier implied wasnt actually as strong as implied, but is once this wave is done. Because that would mean I could tone down my thoughts on how hard endemic covid might be to live with compared to the Omicron wave experience.
 
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Oh and if that last post of mine turns out to be too gloomy in regards future endemic covid, its probably because of an aspect of Omicron which is very well known but somehow doesnt seem to have been fully incorporated into the way people talk about the Omicron variant - it an escape mutant. Even the UK government took Omicron seriously because of that, because it makes the existing wall of immunity less relevant, and its just a question of how less relevant. On this occasion we are lucky that the level of escape is nowhere close to sending us all the way back to square one, and that boosters using the existing vaccines have been able to restrengthen the wall.
 
Early UK analysis of vaccine effectiveness in those aged 65 and over against Omicron, with emphasis on the booster 3rd jabs and any waning after those:


VE against symptomatic disease for cases aged 65 years or older is shown in Figure 1 for those who received a primary course of the ChAdOx1-S (AstraZeneca) (Figure 1a) and BNT162b2 (Pfizer) (Figure 1b) vaccine. In all periods, effectiveness was lower for Omicron compared to Delta. There was minimal or no effect against mild disease with the Omicron variant from 20 weeks after the second dose of either a ChAdOx1-S or BNT162b2 primary course. Among those who had received 2 doses of ChAdOx1-S, at 2 to 4 weeks after a booster dose (either BNT162b2 or mRNA-1273 (Moderna)), VE ranged from around 62% to 65%, dropping to 48% and 56% at 5-9 weeks for the BNT162b2 and mRNA-1273 booster, respectively. For the BNT162b2 booster, VE dropped further to 32% at 10+ weeks. Among those who had received 2 doses of BNT162b2 followed by a BNT162b2 booster, VE was 65% at 2 to 4 weeks post the booster, dropping to 49% at 5 to 9 weeks and 31% at 10+ weeks. For those who had received 2 doses of BNT162b2 followed by a mRNA-1273 booster, VE was 70% at 2 to 4 weeks post the booster, dropping to 57% at 5 to 9 weeks.

There were 98 hospitalisations after 3 doses included in the analysis. Results for hospitalisations for cases aged 65 years or older are shown in Table 1. At 2 to 9 weeks post the third dose, receiving 3 doses of a vaccine was associated with an 89% reduced risk of hospitalisation among symptomatic cases with the Omicron variant. This dropped slightly but remained high at an 85% reduced risk of hospitalisation at 10+ weeks post receipt the third dose. This dropped slightly but remained high at an 85% reduced risk of hospitalisation at 10+ weeks post receipt of the third dose. When combined with VE against symptomatic disease this was equivalent to VE against hospitalisation of 94% 2 to 9 weeks after the booster dose and 89% at 10 weeks post the booster dose in those aged 65 years or older.

These estimates suggest that VE against symptomatic disease with the Omicron variant is significantly lower than compared to the Delta variant and wanes rapidly in those aged 65 years or older. Nevertheless, protection against hospitalisation is much greater than that against symptomatic disease, in particular after a booster dose, where estimated VE against hospitalisation is around 90 to 95%.

These results should be interpreted with caution due to the low numbers and the possible biases related to differences in vaccine coverage and exposure to Omicron in different population groups.

Also covered by this news story:

 
So what do we do? Extend isolation to 10 days? Those findings appear to suggest that would be the right thing to do if you were trying seriously to stop the spread.

Or do you accept that you can't stop the spread, that the costs of trying to do so are too high and you'd fail anyway? Move away from blanket isolation orders and towards something more nuanced and sustainable.

The question is going to be moot soon enough anyway, given that we're probably at or just past peak already.
 
Everyone i know who has had it wouldnt be able to work after 5 days anyway
Omicron or delta?

Delta, sure. Everyone I know who had it (well everyone who had it symptomatically) was knocked sideways for at least a few days.

But omicron (sample size only 3 admittedly), all three said the vaccine was worse.

Govt has stopped reporting omicron proportions now as it reached 95% of all cases by 30 December. Presumably it's even higher than that now. Delta is nearly history, hopefully.

https://assets.publishing.service.g...044522/20211231_OS_Daily_Omicron_Overview.pdf
 
So what do we do? Extend isolation to 10 days? Those findings appear to suggest that would be the right thing to do if you were trying seriously to stop the spread.

Or do you accept that you can't stop the spread, that the costs of trying to do so are too high and you'd fail anyway? Move away from blanket isolation orders and towards something more nuanced and sustainable.

The question is going to be moot soon enough anyway, given that we're probably at or just past peak already.
I expect the authorities look at the widespread behavioural changes that were required to cope with this wave, and graphs like this one for Manchester University NHS Foundation Trust, and conclude that they didnt actually have an enormous amount of wiggle room.

They will move somewhat closer to what you want to see after this wave, not before it or during it. And they wont be sure as to exactly what they can get away with next winter, or what to expect on the future variants front.

Screenshot 2022-01-10 at 13.53.jpg
 
To clarify, when I say not during it, I mean not during the initial upward phase of it. I cant really guess exactly how long they will wait beyond this point before making more changes to the rules. But its reasonable to epect that they will start talking about changes quite some time before actually making any of the largest ones.
 
Plus they already cut it from 10 day to 7 for asymptomatic cases, that was clearly as far as they were prepared to push on that at the time. Now they will probably seek to push a bit more, but maybe still only for asymptomatic cases.

The story was similar with the previous wave - they resisted pressure to do more about the 'pingdemic', despite very loud noises from the right wing press, because they were actually quite reliant on the pingdemic to do a chunk of the heavy lifting in that wave. So they fiddled around rather than demolishing the entire system. Eventually we will reach a point where they are prepared to go so much further, because they think they can make the numbers add up.
 
I see in the news today that they've explicitly tied any changes to self-isolation periods to receiving new advice from the UKHSA. This gives them the usual scientific cover and buys them some time in terms of political pressure, and they also likely have some influence over that timing anyway.

In my book, and possibly theirs, they should wait till they have a better idea about what level cases look like are going to drop down to before doing this stuff, but they might get impatient if that evolution of that picture is slow.
 
There's a preprint on the relative outcomes of Delta and Omicron infections, showing considerably lower rates of hospitalizations, ICU admissions and mortality rates for omicron infections, regardless of vaccination status and known history of infections.


Among cases first tested in outpatient settings, the adjusted hazard ratios for any subsequent hospital admission and symptomatic hospital admission associated with Omicron variant infection were 0.48 (0.36-0.64) and 0.47 (0.35-0.62), respectively. Rates of ICU admission and mortality after an outpatient positive test were 0.26 (0.10-0.73) and 0.09 (0.01-0.75) fold as high among cases with Omicron variant infection as compared to cases with Delta variant infection. Zero cases with Omicron variant infection received mechanical ventilation, as compared to 11 cases with Delta variant infections throughout the period of follow-up (two-sided p<0.001). Median duration of hospital stay was 3.4 (2.8-4.1) days shorter for hospitalized cases with Omicron variant infections as compared to hospitalized patients with Delta variant infections, reflecting a 69.6% (64.0-74.5%) reduction in hospital length of stay. Conclusions: During a period with mixed Delta and Omicron variant circulation, SARS-CoV-2 infections with presumed Omicron variant infection were associated with substantially reduced risk of severe clinical endpoints and shorter durations of hospital stay.
 
Well I was wrong about how much they may delay the decision to reduce the self-isolation period to 5 days.

I havent looked into the detail yet, but Javid announced the change in the commons a little while ago.
 
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