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The home for all non-political Coronavirus (Covid-19) discussions on The Lemon Fool
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This is the home for all non-political Coronavirus (Covid-19) discussions on The Lemon Fool
88V8
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Boosters

#428423

Postby 88V8 » July 18th, 2021, 11:03 am

The well-touted notion that we will be offered booster jabs by autumn.

Push-back from the US govt... who maintain that mRNA vaccines - Pfizer/Moderna - may need no boosters
In a rare move the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) released a joint statement pushing back on the booster claims by Pfizer and BioNTech. Noting virtually all recent COVID-19 deaths and hospitalizations were among unvaccinated individuals, the federal agencies indicated there is currently no evidence to indicate the need for a booster shot.
https://newatlas.com/health-wellbeing/are-boosters-needed-coronavirus-vaccine-mrna-cdc-pfizer/?utm_source=New+Atlas+Subscribers&utm_campaign=568d112cc2-EMAIL_CAMPAIGN_2021_07_14_08_07&utm_medium=email&utm_term=0_65b67362bd-568d112cc2-92456261

If true, not so helpful in the UK where the Pfizer is less used.

But is it true? As linked elsewhere by Mike4, Israel has found a steep drop-off in Pfizer efficacy against the Indian variant
The vaccine protected 64% of people against the illness between June 6 and early July, down from a previous 94%. The drop was observed as the delta variant was spreading in Israel, the Health Ministry said. It also coincided with the lifting of virus restrictions at the start of June.
https://www.bloomberg.com/news/articles ... -ynet-says
Perhaps we're back to the question of how long before infection they were vaccinated, and of course whether the cold chain was intact.

Methinks the boosters question has a way to run.
Perhaps our Astra jabees will be boosted and the Pfizer not.

V8

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Re: Boosters

#428435

Postby Julian » July 18th, 2021, 11:38 am

88V8 wrote:The well-touted notion that we will be offered booster jabs by autumn.

Push-back from the US govt... who maintain that mRNA vaccines - Pfizer/Moderna - may need no boosters
In a rare move the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) released a joint statement pushing back on the booster claims by Pfizer and BioNTech. Noting virtually all recent COVID-19 deaths and hospitalizations were among unvaccinated individuals, the federal agencies indicated there is currently no evidence to indicate the need for a booster shot.
https://newatlas.com/health-wellbeing/are-boosters-needed-coronavirus-vaccine-mrna-cdc-pfizer/?utm_source=New+Atlas+Subscribers&utm_campaign=568d112cc2-EMAIL_CAMPAIGN_2021_07_14_08_07&utm_medium=email&utm_term=0_65b67362bd-568d112cc2-92456261

If true, not so helpful in the UK where the Pfizer is less used.

But is it true? As linked elsewhere by Mike4, Israel has found a steep drop-off in Pfizer efficacy against the Indian variant
The vaccine protected 64% of people against the illness between June 6 and early July, down from a previous 94%. The drop was observed as the delta variant was spreading in Israel, the Health Ministry said. It also coincided with the lifting of virus restrictions at the start of June.
https://www.bloomberg.com/news/articles ... -ynet-says
Perhaps we're back to the question of how long before infection they were vaccinated, and of course whether the cold chain was intact.

Methinks the boosters question has a way to run.
Perhaps our Astra jabees will be boosted and the Pfizer not.

V8

Agreed. It's an interesting and still evolving aspect to all of this at the moment. It's also interesting that pretty much everything that I've been reading about the UK boosters so far seems to be talking about boosting with another dose of the original vaccine formulations, i.e. not tweaking the vaccines yet to try and capture some of the partial escape mutants already seen such as E484K. Imperial College Zoe did a webinar on the Delta variant recently that did briefly discuss tweaking vaccines for new variants. Apparently there are "antigenic cartographers" feverishly at work at the moment creating maps (maybe more like family trees) of all the known variants and they will then use those maps to try and determine just how to tweak the vaccines when the time is deemed appropriate. The video is here - https://www.youtube.com/watch?v=K4PRJNe ... hannel=ZOE - with discussion of vaccine tweaks starting at time index 31:50

- Julian

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Re: Boosters

#428509

Postby 9873210 » July 18th, 2021, 3:19 pm

the federal agencies indicated there is currently no evidence to indicate the need for a booster shot.


This is not a statement about the need for booster shots, it is a statement about the need for evidence.

The FDA has reasonably high standards for what counts as evidence. You can always quibble about a categorical "no evidence", since there's usually at least a shadow of a hint somewhere.

Even if we knew that effectiveness of current vaccines dropped from 97% to 80% it would mean that we would like increased effectiveness, it would not be evidence that any particular booster shot would increase effectiveness.

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Re: Boosters

#429624

Postby Hallucigenia » July 22nd, 2021, 12:58 pm

Julian wrote:
88V8 wrote:Perhaps our Astra jabees will be boosted and the Pfizer not.


Apparently there are "antigenic cartographers" feverishly at work at the moment creating maps (maybe more like family trees) of all the known variants and they will then use those maps to try and determine just how to tweak the vaccines when the time is deemed appropriate.


Supposedly the current thinking in gov.uk is that once the main population is done, they'll give a booster to people who got Oxford-AZ and are high-risk. Maybe not even the former groups 1-9 (ie over 50s plus extras), maybe just over 60s or over 70s. Then see where we are after that - they only need detailed plans for a few months out after all, and data is being collected all the time on which vaccine works to what extent against different variants.

For a taste of the mapping activity see eg :
https://www.medrxiv.org/content/10.1101 ... 21260307v1
Image

Translation into more familiar names :
B.1.1.7 = Alpha, "Kent"
B.1.351 family = Beta, "South Africa"
P.1 family = Gamma, "Brazil"
B.1.617.2 = Delta
B.1.525 = Eta
B.1.526 = Iota, "US"
B.1.617.1 = Kappa

They've not included C.37, Lambda - the new one from Peru that everyone's a bit nervous about.

There's also a recent discovery of a highly conserved epitope away from the receptor binding domain targeted by the vaccines, that is only exposed as the RBD "hinges" to bind to a human cell. It's early days yet, but it offer the possibility of more universal therapies that work against a much wider range of coronaviruses.

https://science.sciencemag.org/content/368/6491/630

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Re: Boosters

#429649

Postby ursaminortaur » July 22nd, 2021, 2:21 pm

The Guardian is reporting that scientists are supporting the case for boosters after finding that antibodies from two doses, of the main vaccines in use, started to wane as early as six weeks after the second shot - in some cases falling more than 50% over 10 weeks.

https://www.theguardian.com/world/2021/jul/22/uk-scientists-back-covid-boosters-as-study-finds-post-jab-falls-in-antibodies

Scientists have backed proposals for Covid boosters in the autumn after blood tests on hundreds of people revealed that protective antibodies can wane substantially within weeks of second vaccine shots being given.

Falls in antibodies after vaccination are expected and do not necessarily mean people are more vulnerable to disease, but the researchers are concerned that if the declines persist the effectiveness of the vaccines may diminish.

The UCL Virus Watch study found that antibodies generated by two doses of the Oxford/AstraZeneca and Pfizer/BioNTech vaccines started to wane as early as six weeks after the second shot, in some cases falling more than 50% over 10 weeks.

The researchers stress that both vaccines are extremely effective against Covid, but say the findings support plans for a booster campaign this autumn, particularly for those who were vaccinated early and with the Oxford/AstraZeneca shot.

“We know levels of antibodies start high and drop substantially,” said Prof Rob Aldridge, an infectious disease epidemiologist at University College London. “We’re concerned that if they carry on dropping at the rate we’ve seen, the protective effects of the vaccines will start to drop too, and the big question is, when is that going to happen?”

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Re: Boosters

#429655

Postby Julian » July 22nd, 2021, 2:36 pm

Fascinating stuff Hallucigenia & ursaminortaur. Thanks to you both.

As an AZ vaccinee there was one bit in that Guardian article that I found somewhat disturbing...

The UCL team analysed blood from 605 vaccinated people mostly in their 50s and 60s. They found that antibody levels varied widely between patients, but a double dose of Pfizer/BioNTech tended to produce far more antibodies against the coronavirus than two shots of the Oxford/AstraZeneca vaccine.

Three to six weeks after full vaccination with Pfizer, antibody levels typically stood at about 7,500 units per millilitre (ml), but more than halved to 3,320 units per ml after 10 weeks. For AstraZeneca, antibody levels peaked at about 1,200 units per ml and typically fell to 190 units per ml after 10 weeks. Since publishing the results in a letter to the Lancet, the researchers have seen the same trend in a further 4,500 participants in the study.


I do realise that there is far more to immunity than simply antibody levels but that difference in levels between Pfizer and AZ seems stark - units per ml typical peaking at 7,200 for Pfizer vs 1,200 for AZ and even more extreme typically decaying after 10 weeks to 3,320 for Pfizer vs 190 for AZ. At the 10 week point that's an over 17-fold difference between typical Pfizer and AZ levels. And I know, T-cells, B-cells and I'm sure lots of other stuff I've never even heard of also play a part but I can't help feeling just a bit disappointed seeing those antibody numbers.

- Julian

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Re: Boosters

#429661

Postby Lootman » July 22nd, 2021, 2:53 pm

Julian wrote:As an AZ vaccinee there was one bit in that Guardian article that I found somewhat disturbing...

The UCL team analysed blood from 605 vaccinated people mostly in their 50s and 60s. They found that antibody levels varied widely between patients, but a double dose of Pfizer/BioNTech tended to produce far more antibodies against the coronavirus than two shots of the Oxford/AstraZeneca vaccine.

Three to six weeks after full vaccination with Pfizer, antibody levels typically stood at about 7,500 units per millilitre (ml), but more than halved to 3,320 units per ml after 10 weeks. For AstraZeneca, antibody levels peaked at about 1,200 units per ml and typically fell to 190 units per ml after 10 weeks. Since publishing the results in a letter to the Lancet, the researchers have seen the same trend in a further 4,500 participants in the study.

I do realise that there is far more to immunity than simply antibody levels but that difference in levels between Pfizer and AZ seems stark - units per ml typical peaking at 7,200 for Pfizer vs 1,200 for AZ and even more extreme typically decaying after 10 weeks to 3,320 for Pfizer vs 190 for AZ. At the 10 week point that's an over 17-fold difference between typical Pfizer and AZ levels. And I know, T-cells, B-cells and I'm sure lots of other stuff I've never even heard of also play a part but I can't help feeling just a bit disappointed seeing those antibody numbers.

The other variable is the time between jabs. US data will be based on a 3-4 week interval between jabs. In the UK it was up to 3 months.

So if the UK needs to boost and the US doesn't, is it just because the AZN vaccine is less effective (for which evidence just grows and grows)? Or is it also the political decision to ignore the science and increase the duration between jabs regardless of vaccine?

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Re: Boosters

#429662

Postby scrumpyjack » July 22nd, 2021, 3:01 pm

I recall reading somewhere that the plan in the UK was to combine it with the winter flu jab and just have one shot that does both for the over 70's etc

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Re: Boosters

#429666

Postby doolally » July 22nd, 2021, 3:07 pm

Lootman wrote:So if the UK needs to boost and the US doesn't, is it just because the AZN vaccine is less effective (for which evidence just grows and grows)? Or is it also the political decision to ignore the science and increase the duration between jabs regardless of vaccine?

Was the science actually ignored? I thought the trials were only done for a 3-4 week interval, there was no data for a 12 week interval. But the scientists understood the need to get as many people vaccinated as quickly as possible and had no objections to stretching out the interval based on their expert judgement.

The alternative would have been to do more clinical trials for various periods, but the extra delay would have been unacceptable.

doolally

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Re: Boosters

#429668

Postby Mike4 » July 22nd, 2021, 3:10 pm

doolally wrote:
Lootman wrote:So if the UK needs to boost and the US doesn't, is it just because the AZN vaccine is less effective (for which evidence just grows and grows)? Or is it also the political decision to ignore the science and increase the duration between jabs regardless of vaccine?

Was the science actually ignored? I thought the trials were only done for a 3-4 week interval, there was no data for a 12 week interval. But the scientists understood the need to get as many people vaccinated as quickly as possible and had no objections to stretching out the interval based on their expert judgement.

The alternative would have been to do more clinical trials for various periods, but the extra delay would have been unacceptable.

doolally


This is my memory of it too. The 4 week interval was chosen instead of 8 or 12 weeks as it meant approval day would be literally one or two months sooner, potentially saving a ton of lives. (Assuming approval was granted at all, that is.)

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Re: Boosters

#429669

Postby pje16 » July 22nd, 2021, 3:11 pm

Interesting article
viewtopic.php?f=98&t=30371&p=429669#p429649
I had AZ and 2nd jab was on 22 April
Two blood test since then (a month apart) both show postive for antibodies, get the results of 3rd test anyday now
Showed negative in two tests after the 1st jab
This testing goes on until April next year so I will now when it's time for a booster !

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Re: Boosters

#429690

Postby Hallucigenia » July 22nd, 2021, 4:13 pm

Julian wrote:Fascinating stuff Hallucigenia & ursaminortaur. Thanks to you both.

As an AZ vaccinee there was one bit in that Guardian article that I found somewhat disturbing...


The basic message seems to be - don't be disturbed, there's lots of other parts of the machinery of which the instructions to make more anti-viral defences are the most important. You have those instructions, you don't need a standing army. It's normal for antibody levels to fall, otherwise you would have blood that is all antibody and no blood! But the protective effect seems to last pretty well.

I've read somewhere one of the UCL team saying something along the lines of - because all the vaccines work 10x better than they need to, this is just eating into your spare capacity rather than seriously affecting your ability to fight the disease. So you're good for now, the worry is more about future variants that might eat up the reduced headroom. But even then you should still have significant protection, and boosters should be available by the time that's a concern.



Just on the timings - remember that the normal gap is 3-4 months, it was only reduced in order to bring forward approval. There were some worries about the mRNA jabs being more time-sensitive as they don't persist in the blood for as long at adenoviral vectors, but in reality the vaccines work so well that the timing doesn't seem to make too much difference. If anything a longer gap should be better.

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Re: Boosters

#429694

Postby Julian » July 22nd, 2021, 4:16 pm

doolally wrote:
Lootman wrote:So if the UK needs to boost and the US doesn't, is it just because the AZN vaccine is less effective (for which evidence just grows and grows)? Or is it also the political decision to ignore the science and increase the duration between jabs regardless of vaccine?

Was the science actually ignored? I thought the trials were only done for a 3-4 week interval, there was no data for a 12 week interval. But the scientists understood the need to get as many people vaccinated as quickly as possible and had no objections to stretching out the interval based on their expert judgement.

The alternative would have been to do more clinical trials for various periods, but the extra delay would have been unacceptable.

doolally

Pretty much everything I have read (and I think I can probably extend that to literally everything I have read) suggests that extending the dosing interval for the AZ vaccine enhanced the efficacy. There were even signals in the data to that effect in the initial phase 2/3 trials where an early cohort, I think maybe at phase 2 but it might have been phase 3, was running a single-dose experiment and once the antibody response induced after the single dose was deemed disappointing they switched the cohort to 2 doses but since first doses were administered over a number of weeks and scheduling second doses took a while for some people it meant that dosing intervals on the second doses varied quite widely so they ended up with data for a range of dosing intervals all the way out to 12 weeks albeit on a fairly low number of patients. Also, that famous half-dose/full-dose cohort that caused so much excitement because it saw significantly better efficacy was also found, on further analysis, to have had longer dosing intervals in the cohort and that extended dosing is now I believe thought to be the more likely cause of the increased efficacy. It was less of a leap of faith extending the interval for the AZ vaccine vs the Pfizer one and I think it's widely believed now that it actually enhanced AZ responses.

Regarding any possible efficacy reduction for Pfizer due to dose interval extension I believe that we see at least ballpark similar figures for efficacy observations done in the UK (extended interval) and the USA and Israel (standard interval as tested in the trials I assume) so I can't see any smoking gun here re UK extending the dosing intervals for either Pfizer or AZ.

- Julian

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Re: Boosters

#430578

Postby pje16 » July 26th, 2021, 8:42 pm

pje16 wrote:Interesting article
viewtopic.php?f=98&t=30371&p=429669#p429649
I had AZ and 2nd jab was on 22 April
Two blood test since then (a month apart) both show postive for antibodies, get the results of 3rd test anyday now
Showed negative in two tests after the 1st jab
This testing goes on until April next year so I will now when it's time for a booster !

Result back today
3 months in and still showing postive :D

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Re: Boosters

#430581

Postby redsturgeon » July 26th, 2021, 8:54 pm

We did antibody tests for the family yesterday. Results as follows:

1. Two pfizer jabs four months ago, strong positive line
2. Had covid in January, one Pfizer jab one month ago, strong positive
3. Two OxAZ jabs two months ago, weak positive line
4. One Pfizer jab two months ago, no positive line
5. No vaccines, no covid, no positive line.

John

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Re: Boosters

#430760

Postby scotia » July 27th, 2021, 5:04 pm

redsturgeon wrote:We did antibody tests for the family yesterday. Results as follows:

1. Two pfizer jabs four months ago, strong positive line
2. Had covid in January, one Pfizer jab one month ago, strong positive
3. Two OxAZ jabs two months ago, weak positive line
4. One Pfizer jab two months ago, no positive line
5. No vaccines, no covid, no positive line.

John

Thanks for the (confusing?) data
It would be interesting to know the ages of the participants.

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Re: Boosters

#430784

Postby redsturgeon » July 27th, 2021, 7:02 pm

scotia wrote:
redsturgeon wrote:We did antibody tests for the family yesterday. Results as follows:

1. Two pfizer jabs four months ago, strong positive line
2. Had covid in January, one Pfizer jab one month ago, strong positive
3. Two OxAZ jabs two months ago, weak positive line
4. One Pfizer jab two months ago, no positive line
5. No vaccines, no covid, no positive line.

John

Thanks for the (confusing?) data
It would be interesting to know the ages of the participants.


1. 50+
2. 20
3. 65
4. 32
5. 28

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Re: Boosters

#430791

Postby Lanark » July 27th, 2021, 7:42 pm

Antibody tests only give a partial picture, it is the T-Cells which are far more important.

  • Antibodies will prevent you from getting ill.
  • T-Cells will give your body the ability to quickly generate new antibodies when needed, that is what will keep you out of hospital.

Indications so far are that T-Cells will remain in the body for years.

A booster shot is therefore more about preventing spread via the vaccinated population which would otherwise affect people who are not vaccinated/or who cant be vaccinated for whatever reason.

Dr John Campbell did an interesting video on YouTube the other day, which explained that the UK (around 12 weeks between shots) are finding that anti bodies are lasting much longer than in the states (who followed the 3 weeks between shots regime).

In the US antibody levels amongst the vaccinated have dropped down to a much lower level over the past 6 months, with the result they are likely to see a significant wave of infections (though not serious illness) amongst the vaccinated going into this autumn/winter.

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Re: Boosters

#430829

Postby 9873210 » July 28th, 2021, 12:05 am

Lanark wrote:Dr John Campbell did an interesting video on YouTube the other day, which explained that the UK (around 12 weeks between shots) are finding that anti bodies are lasting much longer than in the states (who followed the 3 weeks between shots regime).

In the US antibody levels amongst the vaccinated have dropped down to a much lower level over the past 6 months, with the result they are likely to see a significant wave of infections (though not serious illness) amongst the vaccinated going into this autumn/winter.


I believe you are referring to his July 24 report Big US implications from Israel.

His conclusions do not follow from his data.

At 2:30 he says that in the UK full vaccination provides 88% protection against symptomatic infection.
At 2:40 he gives a comparable figure for Israel of 41%.

At 4:40 he says "we do not have full comparable data from the UK at this point". Bear that in mind.
Between 4:40 and 7:20 gives the following data from Israel that shows how protection from infection wanes in Israel after the second dose.

Code: Select all

.               Protection against
.                      symptomatic                         Severe
2nd dose   Infection       disease    Hospitalization     disease
UK overall                     88%                96%

Israel overall   39%           41%                88%         91%
January          16%           16%                82%         86%
February         44%           44%                91%         91%
March            67%           69%                89%         94%
April            75%           79%                88%         84%


Notice we do not have any data showing how protection in the UK changes over time. If we go to Our world in data, we find Israel reached 50% double vaccinated on March 16. The UK reached that level on July 6th more than 3 months later. So if protection wanes starting at the date of the second dose we would expect the UK curve to be three months behind the Israel curve. I.e. the UK overall would be the same as Israel in April because almost everybody in the UK received their second dose in April or later. And that's what we see.

Note that I am not saying whether or not the interval matters. I am saying this data does not allow us to say either way.

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Re: Boosters

#430830

Postby Mike4 » July 28th, 2021, 12:19 am

9873210 wrote:So if protection wanes starting at the date of the second dose we would expect the UK curve to be three months behind the Israel curve. I.e. the UK overall would be the same as Israel in April because almost everybody in the UK received their second dose in April or later. And that's what we see.

Note that I am not saying whether or not the interval matters. I am saying this data does not allow us to say either way.


EXCEPT.... Israel used mostly Pfizer and UK has used mostly AZ, AIUI, and the data does not distinguish, does it?

Just curious really.


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