I think Will is saying that the default position should be stuck to until proven otherwise that mixing and matching provides better protection. Which is the sound position to take.
Coronavirus in the UK - news, lockdown and discussion
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I think Will is saying that the default position should be stuck to until proven otherwise that mixing and matching provides better protection. Which is the sound position to take.
William of Walworth said:Quite correct IMO that mixing vaccines has not generally been happening.
(I thought I'd read that there might? have been odd exceptions in rare circumstances? but that BBC story doesn't mention it)
It's good that there's a study going on to see whether mixing is safe/possible, but I tend to think that the default position should be to stick to the same vaccine for the second.
As I said though, in no way am I not in favour of this vaccine-mix trial.
I was just taking a cautious approach in my not-very-science-savvy mind (
), and saying that my instinct (UNLESS sound trials prove that mixing is as safe or better), would be to stick to the same-vaccine approach.As Teaboy summarised well
Ms Ordinary
randompointlesschemistry
I occasionally get emails from a company called Testing For All because I did an antibody test trial with them.
No idea if the £99 they quote is more or less than your friend paid - or how efficient they are, or even if they're a different company than the government backed one you quote, but anyway...
Brainaddict
slight system overdrive
This from the ZOE app email seems a bit premature, no?
Euurgh, I thought we'd all given up on that statement / concept. Fauci was saying the other day that its just an elusive concept.
How can he know? Isn't the ZOE sample size really small? I think it's great work what they're doing but the sample size always bugged me.
elbows
Well-Known Member
No it cannot be completely abandoned, only certain versions of it, its at the heart of all the modelling exercises. Certain versions of it can be given up on but some of its principals remain important aspects of mass public health epidemiology.
If you abandon the vaccine-based population immunity angles then I dont see where the light at the end of the tunnel is possibly supposed to come from. Traditional epidemic modelling has 'level of population susceptibility' at the very heart of the modelling, and that sort of thing is the reason why even without lockdowns etc, we still see waves that end.
elbows
Well-Known Member
I'll look at what the ZOE bloke said later. Certainly the modelling in March suggested that reaching population immunity, even with the vaccine rollout on track, wasnt something they expected till September-October.
And new variants can scupper those calculations if they evade either natural or vaccine-acquired immunity that has built up.
And new variants can scupper those calculations if they evade either natural or vaccine-acquired immunity that has built up.
elbows
Well-Known Member
Well one region of Brazil. But yes, thats looking like an example of a variant evading previous immunity and destroying their hopes and expectations.
editor
hiraethified
Interesting piece
www.newstatesman.com
Why do pictures of busy outdoor pubs still trigger panic about Covid-19?
We know that outdoor transmission is essentially non-existent, so why are images of people distancing in beer gardens met with sneering online?
www.newstatesman.com
elbows
Well-Known Member
Its been large enough to provide useful results, although I wouldnt like to use it as my only source of info, and the sample size is too small to avoid background noise in some areas such as Northern Ireland.
I got round to watching the video, which reinforced my opinion that I am not a huge fan of the way he describes things. For example he goes on about how rates of infection were already dropping before lockdown, which rather ignores the previous steps on the way to full lockdown, such as the imposition of tier 3 restrictions in London etc, and the earlier imposition of such things in some parts of the North.
But I'd also acknowledge that I sometimes paint too simple a picture myself. Perhaps the sensible approach is to assume that the realities are likely to be somewhere in between the sorts of things he is keen to say, and the sorts of things I and the more cautious modellers will come out with.
And what we all have in common is that it isnt possible to describe with any great certainty what will happen with mutants that can escape immunity, its impossible to properly build such unknowns into our detailed expectations of the future. So for example if something bad happens on that front that changes the game, he will start singing a different tune and will be able to do so without totally contradicting his current optimism and stance.
I'd like to think I have still been able to talk about good news when it is clearly visible in the data, and plenty of whats happened in 2021 in this country so far has been impressive. Its just I cannot help but still be weighed down by various forms of caution, I wont be able to leap ahead to the ultimate end-game good news until its clearly happened and demonstrated an ability to be sustained.
andysays
Love and solidarity
Can anyone explain (ideally in fairly simple terms) why using a combination of two different vaccines would be more effective than two doses of the same one?
elbows
Well-Known Member
Interesting piece
Why do pictures of busy outdoor pubs still trigger panic about Covid-19?
We know that outdoor transmission is essentially non-existent, so why are images of people distancing in beer gardens met with sneering online?
Its not too bad, I suppose its not a million miles away from my stance. I would not have used the words 'effectively non-existent' when describing outdoors transmission, thats going just a little too far. Levels of compliance amongst young people is also quite a bit more complicated than described there, although I'm not going to try to explain that more today. Certainly the article would have benefitted from more of a look into what did sustain the virus over summer and all the factors behind the resurgence. I'm not convinced that lessons in regard how long it takes a resurgence to really build back to high levels takes are visible in that article, and its important to consider that properly when looking at what happened last summer. I'm certainly glad they made mention of indoor settings and misleading ideas about safety measures in such settings, although I dont really agree that we we taught to 'not think twice about friends sat around at a dinner party', as demonstrated by what happened when high-profile people were caught ignoring such rules.
Beyond these picky details yeah, some of whats said in that article does explain why I've tried hard not to go mad at such outdoor imagery or predict immediate doom and new waves within a few weeks.
Supine
Newt Member
if you’re giving your body a lesson in how to identify covid you can give it the exact same lecture twice, or you get a second lecturer to teach the second class. Both systems result in your body learning the lesson.
stdP
One Swiss dinosaur in Polly Gosling's anorak hood
If you're using a weakened version of a virus to deliver a vaccine to your cells, and it works, then on the next your next dose your cells might fight off some of the vaccine before it gets to do its thing. Mixing two vaccines that have different delivery methods ("vectors") means your first shot likely won't prevent the second (different) shot from working with full efficacy.
elbows
Well-Known Member
I'm not in a position to have a proper stab at answering that but for now I'll just say the immune system is complex and not fully understood, and there are signs that some vaccines work better at generating antibodies and others seem to work better at immune responses on a cellular level, eg t-cells which are a different part of the immune system.
Beyond that stuff I'd say the studies also have a different motive - they think that the ongoing nature of vaccination programmes and the logistics of supply mean that its quite likely that people will end up having different vaccines over time. And they want to make sure that doesnt cause problems. This aspect is referred to several times in this sort of news story:
'Mix and match' UK Covid vaccine trial expanded
Using different shots for the first and second doses might give better protection, say experts.
www.bbc.co.uk
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elbows
Well-Known Member
One last comment from me on ZOE videos before I take a break.
I dont think I can properly describe exactly what makes me nervous about some of their stances some of the time. But I am certainly not impressed that they did a youtube video on April 8th which was titled "Third wave in summer unlikely as cases plummet" but then the video itself only makes vague reference to that and offers no real detailed explanation.
I do wish that university modelling of third wave potential was repeatedly performed and published, because otherwise I end up looking back at stuff that gets published around the time of lockdown/lockdown easing decisions, with big gaps in between. At some point I will go back and look at the late March modelling to see if they had made assumptions about expected rates in April which have already become wide of the mark.
I dont think I can properly describe exactly what makes me nervous about some of their stances some of the time. But I am certainly not impressed that they did a youtube video on April 8th which was titled "Third wave in summer unlikely as cases plummet" but then the video itself only makes vague reference to that and offers no real detailed explanation.
I do wish that university modelling of third wave potential was repeatedly performed and published, because otherwise I end up looking back at stuff that gets published around the time of lockdown/lockdown easing decisions, with big gaps in between. At some point I will go back and look at the late March modelling to see if they had made assumptions about expected rates in April which have already become wide of the mark.
teuchter
je suis teuchter
Certainly it would be interesting to see how reality has turned out compared to modelling last month and also earlier in the year.
elbows
Well-Known Member
Its hard to talk about properly though and the window of opportunities to compare modelling to reality dont last very long. Mostly because the modelling is more about looking at multiple scenarios rather than trying to forecast what will happen under the real conditions we actually end up facing. And there are so many variables that I struggle to describe the modelling here in a way that really does justice to all the details.
I suppose the reason I'm not too impressed with some of the language from ZOE is that the March modelling scenarios lead to a range of third wave sizes but as best I can tell these outcomes arent really affected much by how low we manage to push the infection rates at the stage we are at right now. But I suppose that there is a way to connect these in a way that does have implications for any third wave. eg If low numbers seen at the moment provide a guide that vaccine effectiveness is turning out to be on the more impressive end of estimates, then some of the less deadly scenarios become more likely (assuming such scenarios were driven by feeding better vaccination impact into the models.). I probably need to wait till the period where rises in hospitalisations and deaths show up in the models, and then I could take a failure to see such rises as a promising sign.
Never mind, I suppose that I dont consider it likely that any impressive good news at this stage would really leave me in a position where I would start making promises to people about now seeing another wave. At best I'd just be talking about the next wave being on the smaller side. Or the timing being different, eg later if seasonal factors and school summer holidays have quite a large impact.
As usual there are too many graphs for me to do them all justice so here is just one I plucked from a different Universities modelling exercise compared to those I've posted before. I'm only posting such things again now to illustrate why I find ZOE third wave claims to be ill-advised. The numbers in boxes at moments in time reflect the lockdown easing stages, so the first graph only includes the first 2 steps of unlocking happening, and the second sees all the unlocking stages continue as planned.
From https://assets.publishing.service.g...nterim_roadmap_assessment_prior_to_Step_2.pdf
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SpookyFrank
A cheap source of teeth for aquarium gravel
It's particularly unhelpful when you've got anti-lockdown gobshites like Laurence Fox declaring that we've already achieved 'herd immunity' on the basis of zero evidence and zero pertinent scientific understanding.
How we can have herd immunity and rising levels of community transmission at the same time only the gods know.
two sheds
Least noticed poster 2007
Not hugely relevant now but Gupta of the Great Barrington Declaration guff came with the idea there was herd immunity in summer of last year..
www.oxfordstudent.com
‘Herd Immunity’ approach backed by Oxford professor labelled as ‘fallacy’ – The Oxford Student
Professor Sunetra Gupta of the Zoology department has had her proposal of herd immunity as a solution to the Covid-19 pandemic criticised by other leading scientists and student groups. Gupta co-wrote the ‘Great Barrington Declaration’ alongside Harvard’s Professor Martin Kulldorff and Stanford...
www.oxfordstudent.com
teuchter
je suis teuchter
I guess what I'd take from that is that they don't forecast anything noticeable to happen until shortly after step 3 (which I think is the mid-May one). And that timing is not really affected by whether or not step 3 is actually taken.
teuchter
je suis teuchter
There seems to me to be an over-sensitivity about the term "herd immunity". Or maybe it has simply taken on a different meaning from what it had two years ago?
Is it not the case that the whole point of a vaccination programme, ideally, is to obtain a level of herd immunity? It doesn't necessarily imply something that is achieved by allowing a disease to spread freely through the population.
Is it not the case that the whole point of a vaccination programme, ideally, is to obtain a level of herd immunity? It doesn't necessarily imply something that is achieved by allowing a disease to spread freely through the population.
two sheds
Least noticed poster 2007
Yes that's what I thought the correct definition was.
elbows
Well-Known Member
Id break this response down into several different pieces. I think I already talked about this earlier this week. There is stuff your last point alludes to, eg the stuff that relates to this governments botched initial calculations where they thought they would just let the virus rip through the population to achieve such levels. And then there are the realities including the modelling, where levels of population susceptibility are at the very heart of such calculations, why natural course of epidemics and pandemics still features waves that end even without lockdowns and vaccines, etc.
A lot of that stuff I only bring up now with the hope we can put some of it to one side, and focus on reasons to complain about people declaring that herd immunity thresholds have been reached before they actually have. Or even making such claims when they 'might be true' but cannot be fully proven with data yet. As usual I recommend the cautious approach. Claims on that front should be treated with some suspicion, and the suspicion should be multiplied when the person coming out with it has a clear agenda (eg anti-lockdown).
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andysays
Love and solidarity
So at the moment we have a partial level of herd immunity. We won't have the full effective level (at least) until everyone has had (or at a pinch been offered) both vaccinations.
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I think the phrase has morphed into something else because of the perception (whether that was ever their actual approach or not) it was government policy at the start to just let it rip and who was left would immune for evermore.
Its a problem because its clearly an important concept but its become so associated with bad policy that the mere mention of it got the "urrrghh" response from me.
Its a problem because its clearly an important concept but its become so associated with bad policy that the mere mention of it got the "urrrghh" response from me.
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