Developing the Covid-19 vaccine

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shpalman
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Re: Developing the Covid-19 vaccine

Post by shpalman » Mon Feb 08, 2021 6:54 pm

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Herainestold
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Re: Developing the Covid-19 vaccine

Post by Herainestold » Tue Feb 09, 2021 12:27 am


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shpalman
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Re: Developing the Covid-19 vaccine

Post by shpalman » Tue Feb 09, 2021 7:07 am

Herainestold wrote:
Tue Feb 09, 2021 12:27 am
Cool. What is your prediction?
There will be a Hawthorne effect, rather than an effect of the vaccine.
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shpalman
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Re: Developing the Covid-19 vaccine

Post by shpalman » Tue Feb 09, 2021 7:08 am

FB_IMG_1612854210560.jpg
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This is going around. It's unhelpful. These drops are from lockdowns not the vaccine.
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Re: Developing the Covid-19 vaccine

Post by RoMo » Tue Feb 09, 2021 7:29 am

The International Society of Antimicrobial Chemotherapy has a COVID-19 vaccines webinar on 22nd Feb:

https://www.isacwebinars.com/?/program

Herainestold
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Re: Developing the Covid-19 vaccine

Post by Herainestold » Tue Feb 09, 2021 2:51 pm

shpalman wrote:
Tue Feb 09, 2021 7:07 am
Herainestold wrote:
Tue Feb 09, 2021 12:27 am
Cool. What is your prediction?
There will be a Hawthorne effect, rather than an effect of the vaccine.
They need to randomize between AZ and Pfizer.

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Re: Developing the Covid-19 vaccine

Post by shpalman » Tue Feb 09, 2021 3:01 pm

molto tricky

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Re: Developing the Covid-19 vaccine

Post by Gfamily » Tue Feb 09, 2021 3:28 pm

My avatar was a scientific result that was later found to be 'mistaken' - I rarely claim to be 100% correct
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!

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shpalman
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Re: Developing the Covid-19 vaccine

Post by shpalman » Wed Feb 10, 2021 10:37 am

[there is] data from Israel [which] suggests that [the] Pfizer/BioNTech vaccine [is effective in] reducing [the] viral load
Evidence that the coronavirus vaccines being deployed globally are dramatically effective in reducing severe disease and death in symptomatic Covid-19 is abundant. But a big question remains unanswered: can they thwart transmission, in other words stop people from passing on the virus?
And we still don't know, but at least we know that a vaccine against a virus stops you from having so much of that virus.
To evaluate the impact of the vaccine on transmission, researchers compared data from people over 60 years old and those aged 40 to 60, evaluating data from 16,297 people who had tested positive for coronavirus between 1 December and 30 January.

Israel’s vaccine programme began on 20 December. By the time of analysis, more than 75% of those in the older group were likely to have received their first dose, as had about 25% of the younger group.

Although researchers did not know whether each person had been given their first vaccine dose, their hypothesis was that if the vaccine was reducing viral load, then evidence of that would begin to show up in late January but not before, because of the time required by the vaccine to stimulate the immune system.

As expected, in the last two weeks of January the researchers noted a statistically significant fall in the viral load for the individuals aged over 60, compared with the 40-to-60 group, said the study author, Yaniv Erlich, the chief scientific officer of MyHeritage, a company that runs a large coronavirus testing laboratory in Israel.
The paper, which has yet to be peer-reviewed or published in a medical journal, is just an initial study.

Note that this looks at the amount of virus present in people who test positive, so it's basically evidence for the vaccine reducing the severity of the infection. That line in the AstraZeneca publication which indicates 67% efficacy against symptomatic or asymptomatic infections in a certain time window after the first dose would be evidence for their vaccine stopping you from testing positive at all.
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shpalman
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Re: Developing the Covid-19 vaccine

Post by shpalman » Wed Feb 10, 2021 11:25 am

Ok so it doesn't really work against the SA variant but that's fine anyway

And it's not that much worse against the Kent variant and that's relevant to the SA variant somehow!

We know it doesn't protect against mild and moderate disease from the variant but it still might work against severe disease from it! We don't know! Because there weren't any severe cases in the small trial! So here's a load of speculation based on that data we don't have!
Of course, if we are to beat this virus altogether, we will need vaccines that prevent infection and transmission. It’s not yet clear if current vaccines will prevent people who have been vaccinated from transmitting the virus, even for the original variants of the virus. Phase 3 trials have been unable to demonstrate this. But there’s good reason to hope they will – not least because of reports that the AstraZeneca vaccine appears to reduce infections by 67%.
tHe ASTrAZEnECA VAcCine APpEars tO reduce iNFeCTioNS bY 67% does it? THIS IS NOTHING TO DO WITH TRANSMISSIBILITY. THE OTHER APPROVED VACCINES REDUCE INFECTIONS BY >90%. THERE WERE NOT ENOUGH ASYMPTOMATIC CASES IN THE ASTRAZENECA DATA TO SAY ANYTHING USEFUL. STOP THIS.

Oh and that stuff at the end about being able to update vaccines quickly to deal with new variants in a regime of giving annual shots, well, not if your immune system quickly destroys the adenovirus vector which ChAdOx1 uses, which is the suggestion for why it doesn't even work to give two closely-spaced full doses of the vaccine once (and why Sputnik V for example uses different vectors for the two doses). So we'll have to see if after a year the body "forgets" the viral vector.
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Re: Developing the Covid-19 vaccine

Post by Herainestold » Wed Feb 10, 2021 2:04 pm

shpalman wrote:
Wed Feb 10, 2021 11:25 am

Oh and that stuff at the end about being able to update vaccines quickly to deal with new variants in a regime of giving annual shots, well, not if your immune system quickly destroys the adenovirus vector which ChAdOx1 uses, which is the suggestion for why it doesn't even work to give two closely-spaced full doses of the vaccine once (and why Sputnik V for example uses different vectors for the two doses). So we'll have to see if after a year the body "forgets" the viral vector.
The Russians appear to have thought this out more than the others. Maybe adenovirus vaccines need to have the adenovirus vector portion updsted every year, which seems like making a whole new vaccine.

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Re: Developing the Covid-19 vaccine

Post by Woodchopper » Wed Feb 10, 2021 8:12 pm

Info on AstraZeneca trial in South Africa
https://twitter.com/mugecevik/status/13 ... 19712?s=21

tl;dr numbers infected so small we shouldn’t draw conclusions. We need a trial with a decent sample.

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Re: Developing the Covid-19 vaccine

Post by Woodchopper » Wed Feb 10, 2021 8:49 pm

WHO panel recommends use of the AstraZeneca vaccine
https://apps.who.int/iris/rest/bitstrea ... 4/retrieve

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Grumble
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Re: Developing the Covid-19 vaccine

Post by Grumble » Wed Feb 10, 2021 10:26 pm

Serious question here: even if AZ doesn’t work against SA variant it’s worth getting for the protection against the other variants isn’t it? Even if a follow up needs to be done when it’s available.
I know this is vitriol, no solution, spleen venting, but I feel better having screamed, don’t you?

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Re: Developing the Covid-19 vaccine

Post by Herainestold » Wed Feb 10, 2021 11:04 pm

Grumble wrote:
Wed Feb 10, 2021 10:26 pm
Serious question here: even if AZ doesn’t work against SA variant it’s worth getting for the protection against the other variants isn’t it? Even if a follow up needs to be done when it’s available.
I would think so. But what would I know? I'm just a random dude on the interwebz.

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Re: Developing the Covid-19 vaccine

Post by Millennie Al » Thu Feb 11, 2021 3:31 am

Grumble wrote:
Wed Feb 10, 2021 10:26 pm
Serious question here: even if AZ doesn’t work against SA variant it’s worth getting for the protection against the other variants isn’t it? Even if a follow up needs to be done when it’s available.
Medically, of course. It's the same as getting a measles vaccine, which also doesn't protect against any variant of covid. Each vaccine improves your chances of health in general.

However, there may be other factors. For example, if you get this vaccine, maybe it will make you lower priority for another vaccine which is more effective.
Covid-19 - Don't catch it: don't spread it.


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Woodchopper
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Re: Developing the Covid-19 vaccine

Post by Woodchopper » Sun Feb 14, 2021 8:56 pm

Israeli study finds 94% drop in symptomatic COVID-19 cases with Pfizer vaccine
https://www.reuters.com/article/us-heal ... SKBN2AE0Q2

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shpalman
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Re: Developing the Covid-19 vaccine

Post by shpalman » Wed Feb 17, 2021 7:27 pm

Europe has approved the AstraZeneca vaccine for the 55-65 age range, so Italy has too now.
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Re: Developing the Covid-19 vaccine

Post by Woodchopper » Thu Feb 18, 2021 10:20 am

South African Covid variant may cut Pfizer vaccine protection by two-thirds
Study finds fall in antibody activity – but scientists say jab should still protect against severe disease and death

A laboratory study suggests that the South African variant of the coronavirus may reduce antibody protection from the Pfizer/BioNTech vaccine by two-thirds, and it is not clear if the shot will be effective against the mutation, the companies have said.

The study found the vaccine was still able to neutralize the virus and there is not yet evidence from trials in people that the variant reduces vaccine protection, the companies said.

Still, they are making investments and talking to regulators about developing an updated version of their mRNA vaccine, or a booster shot, if needed.
https://www.theguardian.com/world/2021/ ... two-thirds

This makes the Astra Zeneca poor results a bit more worrying. Could be a real effect rather than something due to small sample size etc

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shpalman
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Re: Developing the Covid-19 vaccine

Post by shpalman » Fri Feb 19, 2021 6:12 pm

The authorities have allowed it to enter Phase II

They're hoping to complete Phase III by the summer and start production in September.
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shpalman
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Re: Developing the Covid-19 vaccine

Post by shpalman » Fri Feb 19, 2021 6:55 pm

shpalman wrote:
Tue Feb 02, 2021 7:10 pm
ox-new-Tab2.png

From https://papers.ssrn.com/sol3/papers.cfm ... id=3777268

Their Table 1 doesn't contradict the already-published results on the SD/SD and LD/SD regime.
Now published, so the Guardian can live blog the results again.

https://www.thelancet.com/journals/lanc ... 3/fulltext
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Re: Developing the Covid-19 vaccine

Post by shpalman » Fri Feb 19, 2021 7:17 pm

It seems like the numbers in the tables have been rearranged a bit as compared to the preprint, so we don't have that "67% reduction in transmission" anymore (that particular result, whatever it means, has dropped to 63.9%):
A further important question is whether vaccines can reduce transmission, and therefore combined with physical distancing measures contribute to reductions in human-to-human transmission of the virus. Although transmission studies were not included in the analysis, swabs were obtained from volunteers every week in the UK study, regardless of symptoms, to allow assessment of the overall effect of the vaccine on risk of infection, and thus a surrogate for potential onward transmission. If there was no effect of a vaccine on asymptomatic infection (about a third of infections), it would be expected that an efficacious vaccine would simply convert severe cases to mild cases and mild cases to asymptomatic, with overall NAAT positivity unchanged. Overall NAAT positivity is appropriate to assess whether there is a reduction in the burden of infection. We showed that a single standard dose of the vaccine had efficacy against any NAAT-positive infection, including symptomatic and asymptomatic infections, of 63·9% between day 22 and 90 after first dose, and that, after the second dose, the two standard doses schedule had an efficacy of 49·5%. These data indicate that ChAdOx1 nCoV-19, used in the authorised schedules, might have a substantial effect on transmission by reducing the number of infected individuals in the population
ox-pub-new-Tab2.png
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Re: Developing the Covid-19 vaccine

Post by shpalman » Sat Feb 20, 2021 8:03 pm

seems that the Pfizer one is 75% effective, including asymptomatic cases, two weeks after the first dose according to a study in Israel published as a letter to the Lancet; in the link there's also some data from PHE's new "sums".

https://www.thelancet.com/journals/lanc ... 7/fulltext
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Re: Developing the Covid-19 vaccine

Post by bob sterman » Sun Feb 21, 2021 11:57 am

Article on "second generation" COVID vaccines...

Scientists say clinical trials for ‘variant-proof’ vaccines could start very soon
https://www.theguardian.com/society/202 ... -very-soon

...complete with a really dodgy analogy...
“...if you could aim specifically to generate antibodies in the mucosal linings of the upper airways you could help block the virus from infecting someone or from being passed on,” said Adam Finn, professor of paediatrics at the Bristol Medical School, University of Bristol.

In effect, you would be creating the anti-viral equivalent of those United Nations blue helmet soldiers who control war zones and prevent invasions.
Personally, I don't want my immune responses to be impartial, to rely on the consent of both parties (including the COVID virus) before they are deployed, and to rely primarily on visual deterence rather than enforcement action.

I'd rather have something analogous to a more successful version of the Maginot Line - one that didn't just protect my upper airways (around Strasbourg???) but also my "low countries".

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