Has anyone swapped from AZ to a different virus when getting a booster

[FangsForTheMemory]

I'm wondering if it's easy to arrange. I have had a side effect that is worrying for me as it relates to another condition I have, but I'm not sure how to broach it with my GP.

Do you mean for your 2nd or 3rd dose? Are you in the UK?

I'm in the UK and it would be my third dose of any vaccine.

Afaik all booster doses will be Pfizer or Moderna.

So you won't be offered AZ anyway.

AZ boosters will be rare, they're only offering them to those who can't have the others.

Oh, that's interesting.

www.nhs.uk/conditions/coronavirus-covid-19/coronavirus-vaccination/coronavirus-booster-vaccine/

it'll only be az if you can't have pfizer or moderna. Mostly likely you'll have pfizer.

Why have they changed, out of interest?

@FangsForTheMemory

Why have they changed, out of interest?

I have no idea if this is true but it came from someone I know who is a Head Practice Nurse. It was her belief that as the Pfizer and Moderna vaccines are much harder to store, it was deemed better that the Astra Zenica vaccines were diverted to countries where specialised storage was more of an issue. Hence the use of Pfizer and Moderna for boosters here.

As I say, I have no idea if this is correct but if you think about it, it does make sense. I'm sure someone more knowledgable will be along soon to put me right.

It’s because they found that AZ followed by Pfizer generated a much stronger immune response than either vaccine on its own. About 9x stronger IIRC, so the booster will not just top up immunity but increase it.

@moredogsthansense

It’s because they found that AZ followed by Pfizer generated a much stronger immune response than either vaccine on its own. About 9x stronger IIRC, so the booster will not just top up immunity but increase it.

This. They researched all combinations and AZ followed by pfizer came out best.

I don’t think that’s true that AZ followed by Pfizer generates a much stronger immune response than either vaccine in its own. But it was found that a third dose of Pfizer was well tolerated both by people having previously had two AZ or 2 Pfizer:
www.nihr.ac.uk/news/data-from-nihr-supported-studies-inform-uk-covid-19-booster-programme/28663

And it produced a good immune response in both.

I think that sadly it's obvious that Pfizer turned out to be both more effective and to have fewer side effects.

I also keep reading that an AZ prime followed by Pfizer for second dose is the best combination. But actually Pfizer followed by Pfizer appears to produce the best response with AZ then Pfizer a close second:

www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)01694-9/fulltext

AZ then Pfizer better than AZ AZ but not better than double Pfizer here. But I’m not sure this is what I saw before. Anyway, mixing them is a good thing for those of us who had AZ before, hopefully!