Booster vaccines, eligibility and travel bookings

[ethernet]

I wonder what if a patient said 'I' m travelling to Southern Africa next week' and would the booster - say the 3 month mark? While here, has Thailand undone its asymptomatic test positive, and we stick you with an unnecessary 30K or hospital bill if we feel like it.

 

[jakeseven7]

And in the real world the figures from the USA is that Moderna is a superior booster compared to Pfizer.

Counting down in 3, 2, 1…….

 

[drron]

Pfizer now says with a booster dose their vaccine is effective against Omicron.

Pfizer says booster appears to provide strong protection against omicron

Pfizer and BioNTech announced Wednesday that their coronavirus vaccine appears to provide strong protection against the omicron variant when a booster is received in addition to its initial tw…

thehill.com

 

[N860CR]

Pfizer now says with a booster dose their vaccine is effective against Omicron.

Pfizer says booster appears to provide strong protection against omicron

Pfizer and BioNTech announced Wednesday that their coronavirus vaccine appears to provide strong protection against the omicron variant when a booster is received in addition to its initial tw…

thehill.com

Good news. But certain more so for Pfizer. That’s about several billion doses (and dollars)

 

[jakeseven7]

We all suspect that the interval be ‘officially’ reduced in the next few months by ATAGI… rumours are they are worried about winter numbers and getting enough people boosted in time.

 

[Pushka]

We all suspect that the interval be ‘officially’ reduced in the next few months by ATAGI… rumours are they are worried about winter numbers and getting enough people boosted in time.

Theoretically approx completed by June under current timelines. Probably needs to be by early May. So six months is ok for next few months then rolling back from there.

 

[drron]

Good news. But certain more so for Pfizer. That’s about several billion doses (and dollars)

But this study will not impress someone. It compares a booster with AZ against a booster with Pfizer in people who ha 2 initial Pfizer jabs. AZ comes out on top with very similiar antibody level increase 4 weeks after the booster but twice the increase in T celss with AZ over pfizer.

The data show that heterologous boosting with Ad26.COV2.S or homologous boosting, in individuals who had a primary series of BNT162b2 vaccination at least six months before elicits almost the same final binding and neutralizing antibody titers by week four after the boost to ancestral and newer variants. However, the trajectories of change were different with the two vaccines, showing a steady rise with the former, but a peak followed by the fall from week 2 to week 4 with the latter.

With cellular immunity, the CD8+ T cell frequencies with heterologous Ad26.COV2.S boosting was almost double that achieved with a BNT162b2 booster. Further research will tell how long these cellular responses offer protection against infection. The ability to use heterologous boosters to achieve different types of immune phenotypes is a unique advantage of this approach over the use of homologous boosters.

Immune response of Pfizer vaccinees who received Moderna or Pfizer booster

A new preprint discusses the immune boost resulting from homologous or heterologous booster doses in individuals fully vaccinated with two doses of the Pfizer vaccine.

www.news-medical.net

 

[Lynda2475]

It compares a booster with AZ against a booster with Pfizer in people who ha 2 initial Pfizer jabs. AZ comes out on top with very similiar antibody level increase 4 weeks after the booster but twice the increase in T celss with AZ over pfizer.

Actually that article does not mention AZ at all and the study it links to only included Pfizer and J&J (Ad26.COV2.S).

It was a tiny study which compared "humoral and cellular immune responses in <only> 65 individuals who were vaccinated with the BNT162b2 <Pfizer> vaccine and were boosted after at least 6 months with either Ad26.COV2.S (Johnson & Johnson; N=41) or BNT162b2 (Pfizer; N=24)."

I know J&J is the same category of vaccine as AZ but it is not the same formula. Just like Moderna and Pfizer are both MRNA vaccines but have different formulas and dosages.

Whilst J&J is approved for use in Australia it is not in use in Australia.

 

[Ric]

I spoke to my GP about this today and he said that ATAGI was only allowing booster shots after six months, so he couldn't give me a booster after five months even if I would be travelling overseas to a covid "hotspot" (Europe) and would still be overseas at the six-month mark. He did offer to refer me to an immunologist though.

He suggested that if I was still overseas when my booster became due, I should contact the Australian embassy in whichever country I'm in. Not sure what exactly he expects them to do?

I'm not travelling imminently so will wait and see for now if the government brings forward boosters at some point.

Same here for me. Just wondering if we can get a booster shot overseas when the 6 mths is due, will we be able to get it into AIR? I read that we can for the 1st two jabs but for booster? I think if they can do it for the 1st two jabs, they can do it for the booster.
Wishful thinking?

 

[Lynda2475]

Same here for me.

Time to go shopping for a different GP

 

[Ric]

Time to go shopping for a different GP

Left Oz already!
GP has always been good but we were only just under 4 mths from 2nd jab so maybe that's the hesistancy?

 

[timoh]

Just got my booster shot today - about a month before I hit the 6 months mark. In QLD and went to a GP that had no issue with it since I was going overseas.

 

[Chalkie]

Actually that article does not mention AZ at all and the study it links to only included Pfizer and J&J (Ad26.COV2.S).

It was a tiny study which compared "humoral and cellular immune responses in <only> 65 individuals who were vaccinated with the BNT162b2 <Pfizer> vaccine and were boosted after at least 6 months with either Ad26.COV2.S (Johnson & Johnson; N=41) or BNT162b2 (Pfizer; N=24)."

I know J&J is the same category of vaccine as AZ but it is not the same formula. Just like Moderna and Pfizer are both MRNA vaccines but have different formulas and dosages.

Whilst J&J is approved for use in Australia it is not in use in Australia.

For your edification, here is a complete list of all of the heterologous prime boosting studies of which I am aware, with links to the original papers (where I've been able to source them) or to reports of the study outcomes:

12 May 2021 - UK Com Cov Study Preliminary Report

18 May 2021 - first Spanish study

9 June 2021 - first German study

16 June 2021 - second German study

25 June 2021 - UK Com Cov Study Report

26 July 2021 - South Korea Study

15 October 2021 - US Study

26 October 2021 - Quebec and British Columbia Studies

5 December 2021 - second US study

7 December 2021 - Report on UK Com Cov Study

What is plainly apparent from the studies:

1. Heterologous prime boosting is safe, efficacious and effective.

2. Heterologous prime boosting appears to be a more effective vaccination approach than homologous prime boosting.

3. AZ followed by Moderna is the most effective vaccine combination, from both a surface antibody and T-cell perspective.

 

[Chalkie]

I'm talking about the combination of AZ and mRNA being the best clinically tested combination available right now. There is nothing controversial about that. I'm not talking about double dosed individuals.... as I think you well know...

There's nothing controversial about it at all - it is what the now extensive studies to date have demonstrated.

As for double-dosed individuals and third shots, the conclusion that may reasonably drawn from the heterologous prime boosting studies is that third shots that employ a heterologous vaccination approach are likely more effective than those which employ a homologous approach. There will likely eventually be real world studies along the lines of the Quebec and British Columbia studies referenced in my post above, but they will be some time coming, given third shots have started only relatively recently.

 

[Lynda2475]

.

As for double-dosed individuals and third shots, the conclusion that may reasonably drawn

An assumption on your part, not proven by any means.

Given booster have been happening since start of Sept in USA, longer in Israel and since Oct in UK and Canada plenty of real worl data should be on hand. Note mrna boosters are what is being recommended / preferenced everywhere with good reason.

 

[Chalkie]

.


An assumption on your part, not proven by any means.

Given booster have been happening since start of Sept in USA, longer in Israel and since Oct in UK and Canada plenty of real worl data should be on hand. Note mrna boosters are what is being recommended / preferenced everywhere with good reason.

It can't be "proved" unless there's specific studies and for that matter even real world studies very often do not constitute "proof" in either a scientific or legal sense. But based on my knowledge of matters scientific and legal, I am quite comfortable that there's a reasonable basis for such a hypothesis, based on the extensive heterologous prime boosting studies that have been conducted to date.

If you have them to hand, by all means enlighten us on the real world data and studies that have been published in relation to the most efficacious and effective combinations for third doses. Clinical trials for homologous third doses do not count as heterologous combination studies or data, so don't bother with any of those. They are not studies on heterologous prime boosting, and do not inform that.

 

[drron]

There are a few studies where the conclusion is the Pfizer is the best booster.But all i have read very few measure cellular immunity.And the measurement of antibody levels is done 14 - 15 days after the booster.The studies that measure antibody levels at 4 weeks after the booster show that vaccines that employ a viral vector show an increase in levels at 4 weeks where with Pfizer the levels drop between 2-4 weeks.

Hence why I am going for a Moderna booster after my 2 AZ jabs.

 

[Lynda2475]

It can't be "proved" unless there's specific studies and for that matter

Exactly, so your conclusion is an unproven assumption.

I will be getting an mrna booster.

 

[Chalkie]

Exactly, so your conclusion is an unproven assumption.

I will be getting an mrna booster.

No, it is not an unproven assumption. It is a hypothesis reasonably drawn from a body of scientific literature which has demonstrated that heterologous prime boosting is the most effective vaccination approach. An unproven - and unreasonable - assumption would be assuming that a homologous mRNA regimen is the most effective vaccination approach when the evidence to date suggests that is not the case. By all means get a mRNA third shot if that's what you want, but the evidence to date clearly suggests that a heterologous regimen is the more effective combination.

And do you have the real world data and studies that has been published in relation to the most efficacious and effective combinations for third doses? Clinical trials for homologous third doses do not count as heterologous combination studies or data, so don't bother with any of those. They are not studies on heterologous prime boosting, and do not inform that.

[Oh, and by the way, if you're going to quote for the purposes of trying to make some sort of point, please have the courtesy to quote my whole statement and address it in its entirety. For completeness (and to emphasise what you left out, what I said was "It can't be "proved" unless there's specific studies and for that matter even real world studies very often do not constitute "proof" in either a scientific or legal sense. But based on my knowledge of matters scientific and legal, I am quite comfortable that there's a reasonable basis for such a hypothesis, based on the extensive heterologous prime boosting studies that have been conducted to date."]

 

[Chalkie]

There are a few studies where the conclusion is the Pfizer is the best booster.But all i have read very few measure cellular immunity.And the measurement of antibody levels is done 14 - 15 days after the booster.The studies that measure antibody levels at 4 weeks after the booster show that vaccines that employ a viral vector show an increase in levels at 4 weeks where with Pfizer the levels drop between 2-4 weeks.

Hence why I am going for a Moderna booster after my 2 AZ jabs.

Taking an evidence-based approach, that seems to be the best combination.

Longitudinal studies on cellular immunity have been in short supply. One of the difficulties with those sorts of studies though is the subjects need to be infected to look at T-cell response! I seem to recall that there were some human challenge studies in the UK, but I've not heard whether anything's been published so far.