Covid booster: different or same vaccines?

[Jonetc15]

My wife and I had AstraZeneca for our original Covid-19 jabs. We have now been offered the booster from either PfizerBioNTech or Moderna. I was very pleased that we were having the booster from a different vaccine, being sure that I had read that a different booster would give stronger protection.

I’ve been told by a someone who originally had the Pfizer jab and will have Pfizer for the booster that I may be wrong about the effect of a different booster. Any advice/suggestions will be most gratefully received.

TIA
Jon

[redsturgeon]

The government are just not using any more AZ vaccines (for whatever reason).

But you are correct that it was thought that different vaccines as a boost will give better protection

John

[Lootman]

it was thought that different vaccines as a boost will give better protection

I have seen that claim as well, but is it proven or merely "thought"?

Couldn't that just be a rationalisation of the government not wanting to use the AZN jab any more? Other countries that have administered booster jabs have insisted that it has to be the same vaccine as the original jab. So for example in the US, Pfizer vaccinees are getting a third Pfizer shot. But Moderna vacinees are not getting anything yet because Moderna isn't approved yet for a booster shot.

[Hallucigenia]

Couldn't that just be a rationalisation of the government not wanting to use the AZN jab any more? Other countries that have administered booster jabs have insisted that it has to be the same vaccine as the original jab.

No it's not a rationalisation - it's more that there is reasonable evidence for a booster being a good idea for the vulnerable, and the only approved booster is Pfizer.

But there is some evidence that at the very least heterologous vaccines aren't worse and suggestions they are a bit better - I can't find the paper I'm thinking of in particular that showed that, but this is a "it's no worse than 2 Oxfords" paper :

https://www.thelancet.com/journals/lanc ... 40-6736(21)01694-9/fulltext

And for instance, mix-and-match is official policy in places like Manitoba - the Trudeaux had Oxford followed by Moderna IIRC.

[Hallucigenia]

This wasn't the one I was thinking of, but :
(ChAdOx1-S-nCoV-19 is Oxford/AZ, BNT162b2 is BioNTech/Pfizer)
https://www.nature.com/articles/s41586- ... 4VoOfW4%3D
Here, we show that the heterologous ChAdOx1-S-nCoV-19/BNT162b2 combination confers better protection against Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection than the homologous BNT162b2/BNT162b2 combination in a real-world observational study of healthcare workers (n=13121). To understand the underlying mechanism, we conducted a longitudinal survey of the anti-spike immunity conferred by each vaccine combination. Both combinations induced strong anti-spike antibody (Ab) responses but sera from heterologous vaccinated individuals displayed a stronger neutralizing activity, regardless of the SARS-CoV-2 variant. This enhanced neutralizing potential was correlated with increased frequencies of switched and activated memory B cells recognizing the SARS-CoV-2 Receptor Binding Domain (RBD). The ChAdOx1-S-nCoV-19 vaccine induced a weaker IgG response but a stronger T cell response than the BNT162b2 vaccine after the priming dose, which could explain the complementarity of both vaccines when used in combination.

[XFool]

My wife and I had AstraZeneca for our original Covid-19 jabs. We have now been offered the booster from either PfizerBioNTech or Moderna. I was very pleased that we were having the booster from a different vaccine, being sure that I had read that a different booster would give stronger protection.

I’ve been told by a someone who originally had the Pfizer jab and will have Pfizer for the booster that I may be wrong about the effect of a different booster. Any advice/suggestions will be most gratefully received.

Careful here. Heard on LBC today, from a listener on phone in - something I didn't know. (Haven't verified, but they sounded as if they knew what they were talking about - had a child involved)

It may NOT apply here, however. There are two terms in use: "The Booster vaccination"; "The Third vaccination"

These are not the same thing. The "Booster" is what is being given to people currently - it will be, of course, a third COVID vaccination for them.
The "Third vaccination" is NOT the "Booster", in government/NHS parlance. It is a third jab of COVID vaccine being given to some people, who likely have a compromised immune system. They are different.

It sounds as if this is causing some confusion (with GP receptionists?).

[pje16]

Does anyone know the answer?
You had to get two of the same jab first time round (Feb - July say)

If you get a booster of a different one now why do not need 2 of them this time
I don't know about Moderna, but AZ and Pfizer work in totally different way

[XFool]

The government are just not using any more AZ vaccines (for whatever reason).

Does that include current first or second vaccinations?

[pje16]

Does anyone know the answer?
You had to get two of the same jab first time round (Feb - July say)

If you get a booster of a different one now why do not need 2 of them this time
I don't know about Moderna, but AZ and Pfizer work in totally different way

This page answers my question
seems like if your first 2 were AZ you will get an AZ booster (which makes sense)
https://www.bhf.org.uk/informationsuppo ... er-vaccine

[XFool]

Does anyone know the answer?
You had to get two of the same jab first time round (Feb - July say)

If you get a booster of a different one now why do not need 2 of them this time
I don't know about Moderna, but AZ and Pfizer work in totally different way

This page answers my question
seems like if your first 2 were AZ you will get an AZ booster (which makes sense)
https://www.bhf.org.uk/informationsuppo ... er-vaccine

Well I didn't!

2 x AstraZeneca, 1 x Pfizer Booster

[XFool]

...And from that link:

"What about people who have a weakened immune response?
The JCVI and UK government have recommended that everyone over 12 with a severely weakened immune system is offered a third dose of the Covid-19 vaccine, which is separate from the booster programme."

etc.

[Mike4]

It may NOT apply here, however. There are two terms in use: "The Booster vaccination"; "The Third vaccination"

These are not the same thing. The "Booster" is what is being given to people currently - it will be, of course, a third COVID vaccination for them.
The "Third vaccination" is NOT the "Booster", in government/NHS parlance. It is a third jab of COVID vaccine being given to some people, who likely have a compromised immune system. They are different.

It sounds as if this is causing some confusion (with GP receptionists?).

Well its certainly causing confusion with me!

I'm led to believe the actual contents of the injections are the same as the first and second doses, but from what you say the third is being called a "booster" if given to a healthy person and a "third vaccination" when administered to a person with a compromised immune system.

Do I have that right? Happy to be corrected on any or all of this. Thanks.

[XFool]

It may NOT apply here, however. There are two terms in use: "The Booster vaccination"; "The Third vaccination"

It sounds as if this is causing some confusion (with GP receptionists?).

Well its certainly causing confusion with me!

See my post above. Follow link given in pje's post, it is answered in that article.

"The JCVI have said that this recommendation is an update to the standard dosing schedule for people in this at-risk group, and that they will also be offered a booster vaccine, at a later date.

The recommendation follows early findings from research carried out by the University of Glasgow, showing that 40% of people who are immunosuppressed or immunocompromised do not have a strong enough immune response after two doses of the vaccine."

[redsturgeon]

Does anyone know the answer?
You had to get two of the same jab first time round (Feb - July say)

If you get a booster of a different one now why do not need 2 of them this time
I don't know about Moderna, but AZ and Pfizer work in totally different way

This page answers my question
seems like if your first 2 were AZ you will get an AZ booster (which makes sense)
https://www.bhf.org.uk/informationsuppo ... er-vaccine

It doesn't say that though what it says is:

You are likely to be offered a dose of the Pfizer or Moderna vaccine as a booster dose. Evidence shows that these mRNA vaccines work best as boosters, even if you received a different vaccine for your first two doses. The JCVI reviewed data from several different vaccine combinations before making this recommendation.

You might be offered the AstraZeneca vaccine as a booster dose if you can’t have Pfizer or Moderna. The AstraZeneca vaccine has only been approved as a booster for use in people who had it as their first and second vaccine. 

[pje16]

Does anyone know the answer?
You had to get two of the same jab first time round (Feb - July say)

If you get a booster of a different one now why do not need 2 of them this time
I don't know about Moderna, but AZ and Pfizer work in totally different way

This page answers my question
seems like if your first 2 were AZ you will get an AZ booster (which makes sense)
https://www.bhf.org.uk/informationsuppo ... er-vaccine

It doesn't say that though what it says is:

You are likely to be offered a dose of the Pfizer or Moderna vaccine as a booster dose. Evidence shows that these mRNA vaccines work best as boosters, even if you received a different vaccine for your first two doses. The JCVI reviewed data from several different vaccine combinations before making this recommendation.

You might be offered the AstraZeneca vaccine as a booster dose if you can’t have Pfizer or Moderna. The AstraZeneca vaccine has only been approved as a booster for use in people who had it as their first and second vaccine. 

Please read what I said
I used the word seems
I didn't say it was definite

[redsturgeon]

This page answers my question
seems like if your first 2 were AZ you will get an AZ booster (which makes sense)
https://www.bhf.org.uk/informationsuppo ... er-vaccine

It doesn't say that though what it says is:

You are likely to be offered a dose of the Pfizer or Moderna vaccine as a booster dose. Evidence shows that these mRNA vaccines work best as boosters, even if you received a different vaccine for your first two doses. The JCVI reviewed data from several different vaccine combinations before making this recommendation.

You might be offered the AstraZeneca vaccine as a booster dose if you can’t have Pfizer or Moderna. The AstraZeneca vaccine has only been approved as a booster for use in people who had it as their first and second vaccine. 

Please read what I said
I used the word seems
I didn't say it was definite

I read what you said.

Please read the actual quote

"You are likely to be offered a dose of the Pfizer or Moderna vaccine as a booster dose."

You "might" be offered the AZ booster only "if you can't have Pfizer or Moderna".

And AZ has not been approved as a booster for those who didn't have it first time around.

None of this implies to me that it "seems' like you will get an AZ booster if you had AZ first time around.

John

[Hallucigenia]

Does anyone know the answer?
You had to get two of the same jab first time round (Feb - July say)

If you get a booster of a different one now why do not need 2 of them this time
I don't know about Moderna, but AZ and Pfizer work in totally different way

They don't work in a totally different way. They use different delivery methods, but they both deliver instructions to the body to make a fragment of virus protein, which trains up the body's immune defences. But it's like getting the same letter sent by post and by Fedex.

OK, there's very slight differences - as that paper I posted earlier today explains. But essentially they're doing the same thing.

[pje16]

They don't work in a totally different way. They use different delivery methods, but they both deliver instructions to the body to make a fragment of virus protein, which trains up the body's immune defences. But it's like getting the same letter sent by post and by Fedex.

They do AFAIK
https://www.healthline.com/health/astra ... -they-work
The Pfizer-BioNTech vaccine uses mRNA technology, while the AstraZeneca vaccine uses an adenovirus vector.
quite prepared to be corrected
Your link doesn't work so I can't see what it says

[gryffron]

They don't work in a totally different way.

They do AFAIK
https://www.healthline.com/health/astra ... -they-work
The Pfizer-BioNTech vaccine uses mRNA technology, while the AstraZeneca vaccine uses an adenovirus vector.
quite prepared to be corrected

They work exactly the same way, by using some part of a Coronavirus to stimulate your immune responses. They are manufactured using very different technologies, and use different "bits" of the virus.

Gryff

[pje16]

i see
explained here
https://www.cdc.gov/coronavirus/2019-nc ... -work.html