Developing the Covid-19 vaccine

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bob sterman
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Re: Developing the Covid-19 vaccine

Post by bob sterman » Fri May 21, 2021 7:23 pm

So apparently the EMA has just today announced that people who had blood clots with low blood platelets after receiving the first dose of the AZ vaccine should not receive a second dose of that vaccine.

Would have thought this would have been one of those issues where the precautionary principle would kick in and it wouldn't have taken so long to come up with this advice.

In any case, it would probably be tough to find someone who had clots after the first dose who would be willing to have the second!!!

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Re: Developing the Covid-19 vaccine

Post by Gfamily » Fri May 21, 2021 7:30 pm

Herainestold wrote:
Fri May 21, 2021 6:42 pm
shpalman wrote:
Fri May 21, 2021 3:01 pm
The Novavax coronavirus trial has descended into chaos as exasperated volunteers threaten to drop out because they cannot prove they are fully vaccinated on the NHS app, leaving them unable to travel to Europe.

A similar but smaller problem has been created in Italy for the 600 volunteers trialing the Reithera vaccine whose development appears to have been blocked.
Have they unblinded the trial? Or do trial participants who may have received the placebo think they should be certified as being fully vaxed?
How do you run a late stage covid vaccine phase III trial anyway? Do you use Pfizer instead of a placebo, and where do you test it, India? That would actually be good as we would know it works against the Indian variant.
Can't say for Novavax or Reithera, but the Valneva trial is comparing against the Astra Zenica - though whether this means they're giving AZ to younger testers, I can't say.
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Re: Developing the Covid-19 vaccine

Post by Woodchopper » Fri May 21, 2021 8:03 pm

SAGE document, published 21 May

Vaccines Update Group: Setting up medium-and long-term vaccine strain selection and immunity management for SARS-CoV-2, 4 May 2021

Executive Summary

1. SARS-CoV-2 is evolving antigenically. Some variants are less well neutralized by antibodies raised to current vaccines, and the vaccine efficacy against these variants is lower than for matched virus.

2. Administration of further doses of the current vaccine, which is based on the spike protein from the Wuhan-like virus that emerged in 2019, might maintain and/or boost protection into winter 2021/22, but potentially less so for individuals with a less robust immune response, and less so if substantially antigenically variant viruses circulate widely. Eventually it is likely that the virus will display sufficient substantial antigenic variation and current vaccines will fail to protect against transmission, infection, or even against disease caused by newer variants.

3. Loss of vaccine effectiveness will result in further economic and social costs.

4. A solution is to update vaccines to keep pace with virus evolution, and the newer, more flexible vaccine platforms are particularly suitable for this approach.

5. Additional potential solutions are to invest in developing new vaccination strategies that could induce stronger T cell responses since T cell epitopes might vary less over time.

6. Another strategy would be to search for more broadly protective vaccines, including universal vaccine candidates, multivalent vaccines, and heterologous prime-boost strategies

7. We should also consider whether future vaccination policy will aim to immunize the whole population or only those at risk from severe disease, and how this might be impacted by the long-term accumulation of baseline immunity in the population and long-term evolution of the virus.

8. Effective vaccine updates require coordinated virus and immunity surveillance as well as an effective relationship between public health bodies and the vaccine manufacturers, and an integrated international approach that will integrate into the WHO.
https://www.gov.uk/government/publicati ... 4-may-2021

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Re: Developing the Covid-19 vaccine

Post by gosling » Fri May 21, 2021 9:12 pm

shpalman wrote:
Fri May 21, 2021 3:01 pm
The Novavax coronavirus trial has descended into chaos as exasperated volunteers threaten to drop out because they cannot prove they are fully vaccinated on the NHS app, leaving them unable to travel to Europe.

A similar but smaller problem has been created in Italy for the 600 volunteers trialing the Reithera vaccine whose development appears to have been blocked.
This is interesting - I'm part of this trial and we were told in February that the vaccine would be approved on March 22nd. Obviously it didn't. Then when we were given our 'crossover' jabs in April, we were told it would get approved in May and that they'd send our info to the NHS so we'd be registered as being vaccinated.

However, I don't have much sympathy for the people in the article. When I signed up in November, we knew it was a 12-month trial and at that point we would only get placebo or vaccine. We wouldn't get unblinded until the end of the 12 months. It was only when the other vaccines got approval and people started being called by the NHS, that they offered the crossover - vaccine for people who had had placebo and vice versa.

I've got my 6-month follow-up on Monday, I'll be interested to hear what they say then. All the people working at my location are lovely. I hope no-one's giving them a hard time for just telling us what the company has told them.

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Re: Developing the Covid-19 vaccine

Post by Millennie Al » Sat May 22, 2021 12:04 am

(Novavax trial)
Herainestold wrote:
Fri May 21, 2021 6:42 pm
Have they unblinded the trial? Or do trial participants who may have received the placebo think they should be certified as being fully vaxed?
How do you run a late stage covid vaccine phase III trial anyway? Do you use Pfizer instead of a placebo, and where do you test it, India? That would actually be good as we would know it works against the Indian variant.
Now that there are approved vaccines which are better than placebo, it's unlikely to be ethical to run any more comparisons of a new vaccine against a placebo - they should be comparing the new vaccine with a known good one. As such, parrticipants can know that they have had a vaccine - just not which one. Of course this poses a problem - if a vaccine certificate is needed, should people in such a trial get one? After all, the whole purpose is to see if the new vaccine works, so it seems wrong to certify the participants who get it, while certifying the ones who don't results in everyone being unblinded.
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Re: Developing the Covid-19 vaccine

Post by Herainestold » Sat May 22, 2021 12:48 am

Millennie Al wrote:
Sat May 22, 2021 12:04 am
(Novavax trial)
Herainestold wrote:
Fri May 21, 2021 6:42 pm
Have they unblinded the trial? Or do trial participants who may have received the placebo think they should be certified as being fully vaxed?
How do you run a late stage covid vaccine phase III trial anyway? Do you use Pfizer instead of a placebo, and where do you test it, India? That would actually be good as we would know it works against the Indian variant.
Now that there are approved vaccines which are better than placebo, it's unlikely to be ethical to run any more comparisons of a new vaccine against a placebo - they should be comparing the new vaccine with a known good one. As such, parrticipants can know that they have had a vaccine - just not which one. Of course this poses a problem - if a vaccine certificate is needed, should people in such a trial get one? After all, the whole purpose is to see if the new vaccine works, so it seems wrong to certify the participants who get it, while certifying the ones who don't results in everyone being unblinded.
Okay < I see from gosling's post that the Novavax trial has gone over to a cross over type of trial. That explains it.
I totally understand that with effective vaccines it would be unethical to give trial participants a placebo. I just figured it would be Pfizer
as that is the 'gold standard' of Covid vaccines at the moment. It seems there might be an ethical problem with giving people AZ instead of Pfizer as the
alternate vaccine. There is a very small risk of fatal blood clots with AZ, that as far as I know does not exist with Pfizer. I got AZ and i am totally happy to accept the risk, but is it proper to submit people to that small risk if there is an alternative?

You still have to do the trial somewhere where there is risk of catching covid, or it makes no sense.
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Re: Developing the Covid-19 vaccine

Post by Sciolus » Sat May 22, 2021 9:49 am

Millennie Al wrote:
Sat May 22, 2021 12:04 am
Now that there are approved vaccines which are better than placebo, it's unlikely to be ethical to run any more comparisons of a new vaccine against a placebo - they should be comparing the new vaccine with a known good one. As such, parrticipants can know that they have had a vaccine - just not which one. Of course this poses a problem - if a vaccine certificate is needed, should people in such a trial get one? After all, the whole purpose is to see if the new vaccine works, so it seems wrong to certify the participants who get it, while certifying the ones who don't results in everyone being unblinded.
f.cking hell, it's not difficult. Vaccine certificates are a risk management tool to balance risk of unvaccinated people spreading infection against benefits of normal life. They are not meant to be some kind of shibboleth. So the small number of people who are edge cases -- participating in trials, unable to get jabbed for one of the tiny number of medical reasons, or whatever -- just get a certificate saying they are in this special category and should be treated as though vaccinated.

This rant is mainly aimed not at Al but at the myriad moronic MPs and commentators who bang on about passports being unworkable because of a tiny number of edge cases, missing the obvious solution.

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Re: Developing the Covid-19 vaccine

Post by shpalman » Sat May 22, 2021 10:17 am

Sciolus wrote:
Sat May 22, 2021 9:49 am
Millennie Al wrote:
Sat May 22, 2021 12:04 am
Now that there are approved vaccines which are better than placebo, it's unlikely to be ethical to run any more comparisons of a new vaccine against a placebo - they should be comparing the new vaccine with a known good one. As such, parrticipants can know that they have had a vaccine - just not which one. Of course this poses a problem - if a vaccine certificate is needed, should people in such a trial get one? After all, the whole purpose is to see if the new vaccine works, so it seems wrong to certify the participants who get it, while certifying the ones who don't results in everyone being unblinded.
f.cking hell, it's not difficult. Vaccine certificates are a risk management tool to balance risk of unvaccinated people spreading infection against benefits of normal life. They are not meant to be some kind of shibboleth. So the small number of people who are edge cases -- participating in trials, unable to get jabbed for one of the tiny number of medical reasons, or whatever -- just get a certificate saying they are in this special category and should be treated as though vaccinated.

This rant is mainly aimed not at Al but at the myriad moronic MPs and commentators who bang on about passports being unworkable because of a tiny number of edge cases, missing the obvious solution.
Or we can implement subsidized/free testing for that small number of people so they can earn their Green Pass with a "negative PCR test within the previous 48 hours" like anyone else.

Maybe we didn't already link to Efficacy of NVX-CoV2373 Covid-19 Vaccine against the B.1.351 Variant.

DOI: 10.1056/NEJMoa2103055
Of 6324 participants who underwent screening, 4387 received at least one injection of vaccine or placebo. Approximately 30% of the participants were seropositive for SARS-CoV-2 at baseline. Among 2684 baseline seronegative participants (94% HIV-negative and 6% HIV-positive), predominantly mild-to-moderate Covid-19 developed in 15 participants in the vaccine group and in 29 in the placebo group (vaccine efficacy, 49.4%; 95% confidence interval [CI], 6.1 to 72.8). Vaccine efficacy among HIV-negative participants was 60.1% (95% CI, 19.9 to 80.1). Of 41 sequenced isolates, 38 (92.7%) were the B.1.351 variant. Post hoc vaccine efficacy against B.1.351 was 51.0% (95% CI, −0.6 to 76.2) among the HIV-negative participants. Preliminary local and systemic reactogenicity events were more common in the vaccine group; serious adverse events were rare in both groups.
molto tricky

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Re: Developing the Covid-19 vaccine

Post by shpalman » Sat May 22, 2021 11:35 am

Assurances that I would be looked after as a participant in the Novavax trial now sound hollow
My turn for an authorised jab came up in January and, as promised, the researchers “unblinded” me and told me that I had had the live trial vaccine in my body, not the placebo. Government advice was that it might be unsafe to put another vaccine into my body.

The researchers were keen for me to stay in the study, and assured me that Novavax was expected to become an approved vaccine in April, or May at the latest, after which time I would go on the national vaccine register and could have a vaccine passport just like those who had been vaccinated in the normal way.

So, with many misgivings, I turned down the Oxford AstraZeneca vaccine I was offered, and tried not to worry as I heard nothing about Novavax applying for approval.

Alarm bells began to ring last week when an email arrived from a researcher on the team to say Novavax would not be seeking MHRA approval until later in the year.
molto tricky

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Re: Developing the Covid-19 vaccine

Post by shpalman » Sat May 22, 2021 3:01 pm

Actually it's interesting/strange that a positive antibody test (along with a negative PCR if necessary) isn't being considered for the Green Pass.
molto tricky

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Re: Developing the Covid-19 vaccine

Post by Woodchopper » Sun May 23, 2021 4:27 pm


New tonight is vaccine effectiveness (VE) analysis by vaccine - Pfizer and Oxford/AZ

This shows a difference in effectiveness (symptomatic infection) after Dose 2

📌AZ: 60% for B.1.617.2 vs 66% for B.1.1.7
📌Pfizer: 88% for B.1.617.2 vs 93% for B.1.17
https://twitter.com/kallmemeg/status/13 ... 46149?s=21

Much more in the thread

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Re: Developing the Covid-19 vaccine

Post by Bird on a Fire » Mon May 24, 2021 10:31 am

Adding in the confidence intervals of those estimates:
Woodchopper wrote:
Sun May 23, 2021 4:27 pm

New tonight is vaccine effectiveness (VE) analysis by vaccine - Pfizer and Oxford/AZ

This shows a difference in effectiveness (symptomatic infection) after Dose 2

📌AZ: 60% (30-77%) for B.1.617.2 vs 66% (54-75%) for B.1.1.7
📌Pfizer: 88% (78-93%) for B.1.617.2 vs 93% (90-95%) for B.1.17
https://twitter.com/kallmemeg/status/13 ... 46149?s=21

Much more in the thread
While it shows that AZ is less effective than Pfizer, it doesn't show difference in effectiveness between the variants for AZ.

The preprint she's got that data from states as much:
In the ‘any vaccine’analysis, effectiveness was notably lower after 1 dose of vaccine with B.1.617.2 cases 33.5% (95%CI: 20.6 to 44.3) compared to B.1.1.7 cases 51.1% (95%CI: 47.3 to 54.7). Results for dose 1 were similar for both vaccines. Following dose 2, the reduction in vaccine effectiveness was much smaller and non-significant: 86.8% (95%CI: 83.1 to 89.6) with B.1.1.7 and 80.9 (70.7 to 87.6) with B.1.617.2. With BNT162b2 there was a small reduction in effectiveness post dose 2 from 93.4% (95%CI: 90.4 to 95.5) with B.1.1.7 to 87.9% (95%CI:78.2 to 93.2)with B.1.617.2. Numbers vaccinated with 2 doses of ChAdOx1 were smaller and the overall 2 dose vaccine effectiveness was lower than with BNT162b2 however the difference in vaccine effectiveness between B.1.1.7 and B.1.617.2 was small and non-significant: 66.1% (95% CI: 54.0 to 75.0) and 59.8% (95%CI: 28.9 to 77.3) respectively.
I would guess that with a bigger sample size they might well find a small difference, but they haven't.
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Re: Developing the Covid-19 vaccine

Post by Woodchopper » Wed May 26, 2021 6:36 pm

AZ and JJ clotting problems explained, apparently.

During the last months many countries have started the immunization of millions of people by using vector-based vaccines. Unfortunately, severe side effects became overt during these vaccination campaigns: cerebral venous sinus thromboses (CVST), absolutely rare under normal life conditions, were found as a severe side effect that occured 4-14 days after first vaccinations. Besides CVST, Splanchnic Vein Thrombosis (SVT) was also observed. This type of adverse event has not been observed in the clinical studies of AstraZeneca, and therefore led immediately to a halt in vaccinations in several european countries. These events were mostly associated with thrombocytopenia, and thus, similar to the well-known Heparin-induced thrombo­cytopenia (HIT). Meanwhile, scientists have proposed a mechanism to explain this vaccine-induced thrombocytopenia. However, they do not provide a satisfactory explanation for the late thromboembolic events. Here, we present data that may explain these severe side effects which have been attributed to adenoviral vaccines. According to our results, transcription of wildtype and codon-optimized Spike open reading frames enables alternative splice events that lead to C-terminal truncated, soluble Spike protein variants. These soluble Spike variants may initiate severe side effects when binding to ACE2-expressing endothelial cells in blood vessels. In analogy to the thromboembolic events caused by Spike protein encoded by the SARS-CoV-2 virus, we termed the underlying disease mechanism the “Vaccine-Induced Covid-19 Mimicry” syndrome (VIC19M syndrome).
https://www.researchsquare.com/article/rs-558954/v1

In the news:

Rolf Marschalek, a professor at Goethe university in Frankfurt who has been leading research into the rare condition since March, said his research showed that the problem sat with the adenovirus vectors that both vaccines use to deliver the spike protein of the Sars-Cov-2 virus into the body.

The delivery mechanism means the vaccines send the spike protein into the cell nucleus rather than the cytosol fluid found inside the cell where the virus normally produces proteins

[...]

Once inside the cell nucleus, certain parts of the spike protein splice, or split apart, creating mutant versions, which are unable to bind to the cell membrane where important immunisation takes place. The floating mutant proteins are instead secreted by cells into the body, triggering blood clots in roughly one in 100,000 people, according to Marschalek’s theory.

In contrast, mRNA-based vaccines, such as the jabs developed by BioNTech/Pfizer and Moderna, deliver the spike’s genetic material to the cell fluid and it never enters the nucleus.

“When these . . . virus genes are in the nucleus they can create some problems,” Marschalek told the Financial Times.
https://www.ft.com/content/f76eb802-ec0 ... 50115d0577

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Re: Developing the Covid-19 vaccine

Post by raven » Fri May 28, 2021 11:25 am

Thanks for posting that, Woodchopper. Really interesting.

If, like I was hoping, the cause is the adenovirus vector, how easy is it for AZ to switch to another vector? That would mean going through the trial process again, I guess.

Also, if they're right about altered spike protein causing problems maybe that's a clue to why some people get clotting with Covid itself.

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Re: Developing the Covid-19 vaccine

Post by tom p » Fri May 28, 2021 2:05 pm

raven wrote:
Fri May 28, 2021 11:25 am
Thanks for posting that, Woodchopper. Really interesting.

If, like I was hoping, the cause is the adenovirus vector, how easy is it for AZ to switch to another vector? That would mean going through the trial process again, I guess.
Yes it would. It's basically starting all over again from scratch, when there's already other vaccines & the rates of COVID are falling throughout most of the world.
You're talking years to run such a study now, rather than months

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Re: Developing the Covid-19 vaccine

Post by Herainestold » Fri Jun 04, 2021 6:16 pm

How quickly can vaccines be adjusted for new variants? Is it weeks, months, years? What is the rate limiting step, is it formulating the new vaccine, testing it, manufacturing it, or gaining regulatory approval? It seems like the new variants are coming about every two months, how can vccines possibly stay ahead at this pace?
Delta changes everything.

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Re: Developing the Covid-19 vaccine

Post by JQH » Sat Jun 05, 2021 8:36 am

Herainestold wrote:
Fri Jun 04, 2021 6:16 pm
How quickly can vaccines be adjusted for new variants? Is it weeks, months, years? What is the rate limiting step, is it formulating the new vaccine, testing it, manufacturing it, or gaining regulatory approval? It seems like the new variants are coming about every two months, how can vccines possibly stay ahead at this pace?
The vaccines appear to have some effect on the new variants. There's no reason why new vaccines can't be produced as quickly as the current crop. Un-knot your knickers.
And remember that if you botch the exit, the carnival of reaction may be coming to a town near you.

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Re: Developing the Covid-19 vaccine

Post by Woodchopper » Sat Jun 05, 2021 9:55 am

Herainestold wrote:
Fri Jun 04, 2021 6:16 pm
How quickly can vaccines be adjusted for new variants? Is it weeks, months, years? What is the rate limiting step, is it formulating the new vaccine, testing it, manufacturing it, or gaining regulatory approval? It seems like the new variants are coming about every two months, how can vccines possibly stay ahead at this pace?
As far as I know, the RNA vaccines (eg Pfizer) can be tweaked very quickly. If its a minor update they won't need a new round of clinical trials. The delay will come from production and distribution.

Mass vaccination started about six months ago and double doses of Pfizer, AZ etc are still 90% or more effective against the new strains. It may become necessary for people to have booster shots, that all depends upon how the virus evolves, and that is very difficult to predice. But at the moment there is no reason to believe that they will be needed every few months. The SARS-COV2-2019 virus appears to evolve more slowly than does Influenza, so we may not need a new vaccine every year.

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Re: Developing the Covid-19 vaccine

Post by Millennie Al » Sun Jun 06, 2021 1:15 am

Herainestold wrote:
Fri Jun 04, 2021 6:16 pm
How quickly can vaccines be adjusted for new variants? Is it weeks, months, years?
Yes. All of them.
What is the rate limiting step, is it formulating the new vaccine, testing it, manufacturing it, or gaining regulatory approval? It seems like the new variants are coming about every two months, how can vccines possibly stay ahead at this pace?
The Oxford/AZ vaccine started development in mid January 2020 (https://covid19vaccinetrial.co.uk/about) and the first trial participants were getting doses by the and of April. The delay between that and approval was due to the trials and regulatory bodies scrutinising the results. If you have been following this forum creafully, you will have seen some of the figures which show that, despite recruiting 40,000 participants it took quite a few months before even the unvaccinated half had accumulated 100 Covid-19 cases. That was one part of the delay.

But the development didn't start from nothing. The adenovirus vector had already been developed for use in other vaccines. So the time it takes to develop a new vaccine is highly variable. If you just want a minor tweak that does not need a full clinical trial, you can get than in a couple of months. A bigger change, and you may need a year (the time from January 2020 to first approval in November 2020). But if you need the whole thing done from scratch, it could be many years with no upper limit - we still don't have an approved HIV vaccine despite research starting in the 1980's.

Fortunately, variants seen so far are not sufficiently different from one another to need new vaccines, which is consistent with coronaviruses in general not being as quick to mutate as influenza viruses.
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Re: Developing the Covid-19 vaccine

Post by Herainestold » Sun Jun 06, 2021 1:37 am

JQH wrote:
Sat Jun 05, 2021 8:36 am
Herainestold wrote:
Fri Jun 04, 2021 6:16 pm
How quickly can vaccines be adjusted for new variants? Is it weeks, months, years? What is the rate limiting step, is it formulating the new vaccine, testing it, manufacturing it, or gaining regulatory approval? It seems like the new variants are coming about every two months, how can vccines possibly stay ahead at this pace?
The vaccines appear to have some effect on the new variants. There's no reason why new vaccines can't be produced as quickly as the current crop. Un-knot your knickers.
I am pretty pessimistic about getting out of this pandemic treadmill. Every time there is light at the end of the tunnel, a new variant and there we go again.
Delta changes everything.

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Re: Developing the Covid-19 vaccine

Post by Herainestold » Sun Jun 06, 2021 1:43 am

Woodchopper wrote:
Sat Jun 05, 2021 9:55 am
Herainestold wrote:
Fri Jun 04, 2021 6:16 pm
How quickly can vaccines be adjusted for new variants? Is it weeks, months, years? What is the rate limiting step, is it formulating the new vaccine, testing it, manufacturing it, or gaining regulatory approval? It seems like the new variants are coming about every two months, how can vccines possibly stay ahead at this pace?
As far as I know, the RNA vaccines (eg Pfizer) can be tweaked very quickly. If its a minor update they won't need a new round of clinical trials. The delay will come from production and distribution.

Mass vaccination started about six months ago and double doses of Pfizer, AZ etc are still 90% or more effective against the new strains. It may become necessary for people to have booster shots, that all depends upon how the virus evolves, and that is very difficult to predice. But at the moment there is no reason to believe that they will be needed every few months. The SARS-COV2-2019 virus appears to evolve more slowly than does Influenza, so we may not need a new vaccine every year.
So if this is true, why are we seeing new virus surges every 2-3 months? We don't see that with influenza. Despite much greater vaccine coverage than we see with flu, we see new cases and major waves, in places like Chile and Seychelles with greater vaccine coverage than we have in UK.
It seems like a treadmill we will never get off.

We've seen what new variants have done to India, we are just waiting to see what they do everywhere else.
Delta changes everything.

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Re: Developing the Covid-19 vaccine

Post by Woodchopper » Sun Jun 06, 2021 7:06 am

Herainestold wrote:
Sun Jun 06, 2021 1:43 am
Woodchopper wrote:
Sat Jun 05, 2021 9:55 am
Herainestold wrote:
Fri Jun 04, 2021 6:16 pm
How quickly can vaccines be adjusted for new variants? Is it weeks, months, years? What is the rate limiting step, is it formulating the new vaccine, testing it, manufacturing it, or gaining regulatory approval? It seems like the new variants are coming about every two months, how can vccines possibly stay ahead at this pace?
As far as I know, the RNA vaccines (eg Pfizer) can be tweaked very quickly. If its a minor update they won't need a new round of clinical trials. The delay will come from production and distribution.

Mass vaccination started about six months ago and double doses of Pfizer, AZ etc are still 90% or more effective against the new strains. It may become necessary for people to have booster shots, that all depends upon how the virus evolves, and that is very difficult to predice. But at the moment there is no reason to believe that they will be needed every few months. The SARS-COV2-2019 virus appears to evolve more slowly than does Influenza, so we may not need a new vaccine every year.
So if this is true, why are we seeing new virus surges every 2-3 months? We don't see that with influenza. Despite much greater vaccine coverage than we see with flu, we see new cases and major waves, in places like Chile and Seychelles with greater vaccine coverage than we have in UK.
It seems like a treadmill we will never get off.

We've seen what new variants have done to India, we are just waiting to see what they do everywhere else.

We do see rapid evolution of new strains of Influenza. However, it’s usually a much less virulent disease to the new strains don’t make the headlines.

Rising cases in Chile and the Seychelles appear to be among people who weren’t properly vaccinated:

In the Seychelles:
Of those who needed admission to hospital, 80% were people who hadn't been vaccinated
https://www.bbc.com/news/57148348

In Chile, cases appeared to rise after people started mixing after a single dose which didn’t offer much protection. Most people were also given one of the vaccines which has lower effectiveness. https://www.bmj.com/content/373/bmj.n1023

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Re: Developing the Covid-19 vaccine

Post by bob sterman » Sun Jun 06, 2021 7:10 am

Herainestold wrote:
Sun Jun 06, 2021 1:43 am
So if this is true, why are we seeing new virus surges every 2-3 months? We don't see that with influenza. Despite much greater vaccine coverage than we see with flu, we see new cases and major waves, in places like Chile and Seychelles with greater vaccine coverage than we have in UK.
It seems like a treadmill we will never get off.
Seychelles used a lot of Sinopharm and some AZ. Chile used a lot of Sinovac.

Are there any major new waves in populations widely vaccinated with mRNA alternatives?

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jdc
Hilda Ogden
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Re: Developing the Covid-19 vaccine

Post by jdc » Sun Jun 06, 2021 3:36 pm

Re development time for tweaked vaccines:

they announced in Jan that they were working on a 'new' Moderna vaccine https://www.cnbc.com/2021/01/28/why-mrn ... iants.html

the first doses were administered to trial participants end Mar https://news.emory.edu/stories/2021/04/ ... index.html

and the trial is scheduled to complete end Aug https://clinicaltrials.gov/ct2/show/NCT04785144 with initial data mentioned here https://investors.modernatx.com/news-re ... t-sars-cov
a single 50 µg dose of mRNA-1273 or mRNA-1273.351 given as a booster to previously vaccinated individuals increased neutralizing antibody titer responses against SARS-CoV-2 and two variants of concern, B.1.351 (first identified in South Africa) and P.1 (first identified in Brazil). A booster dose of mRNA-1273.351, the Company’s strain-matched booster, achieved higher neutralizing antibody titers against the B.1.351 variant of concern than a booster dose of mRNA-1273. A manuscript describing these preliminary results has been submitted as a preprint to medRxiv and will be submitted for peer-reviewed publication upon completion of the multivalent mRNA-1273.211 booster arm.
And that medRxiv paper is here https://www.medrxiv.org/content/10.1101 ... .full-text

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Hilda Ogden
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Re: Developing the Covid-19 vaccine

Post by jdc » Sun Jun 06, 2021 5:01 pm

Herainestold wrote:
Sun Jun 06, 2021 1:43 am
So if this is true, why are we seeing new virus surges every 2-3 months? We don't see that with influenza.
Have you considered seasonality? Maybe flu has a narrower range of temp/humidity that it can survive in?

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