Why not 2 doses of booster for people who had AstraZeneca?

[OriginalM]

Just wondering why only 1 booster dose is given to people who had the 2 AstraZeneca vaccines?
As AZ wanes off more so than Pfizer at around 6 months then if only 1 booster dose of Pfizer is given then wouldn't that leave people half protected and in a more vulnerable position than those who had all 3 Pfizer jabs?

No, the stats show over 90% protection from serious illness regardless of whether you had AZ, Pfizer or Moderna first time around

If you have a Pfizer booster

It’s not necessary.

Science will give you the full answer.

This is why

I heard someone from Astra Zeneca on the radio and he said that their vaccine produces more T cells and has prevented many more serious cases of Covid.

If it turns out people who had AZ initially need a second booster then presumably that may well happen. There's no evidence for that yet as we're only partway through the initial booster rollout.
The OPs question is premature.

@OriginalM

Just wondering why only 1 booster dose is given to people who had the 2 AstraZeneca vaccines? As AZ wanes off more so than Pfizer at around 6 months then if only 1 booster dose of Pfizer is given then wouldn't that leave people half protected and in a more vulnerable position than those who had all 3 Pfizer jabs?

From everything I've heard the current research/evidence doesn't support that theory. It's not how the jabs work but as I'm not a scientist I'm only repeating what I've heard the experts say

My understanding is that AZ provides better long term immunity rather than just antibodies.

@MaxNormal

My understanding is that AZ provides better long term immunity rather than just antibodies.

Who knows, it might conceivably even turn out that it would be a good idea for people who had Pfizer or Moderna initially to have a shot or two of AZ at some point later.

ErrolTheDragon yes tbh I'm not betting my house on that statement, given how quickly information is changing at present.

Yes.
All they can do is what they're doing - try to proceed at each stage in accordance with the evidence available at that point.

@MaxNormal

My understanding is that AZ provides better long term immunity rather than just antibodies.

Well, I thought this, but it appears to wane a lot faster, so I am not sure now?

Waning is complicated. Antibodies wane quickly with all the jabs. It seems they wane more quickly with Pfizer but from a higher starting point. T and B cell immunity is more long lasting and obviously the data on this is only just coming through.

If you have lots of antibodies i.e. after a booster, you have more protection in fighting off an infection quickly as you don't need to actually make the antibodies and may never develop an infection or just get a mild or asymptomatic case.

Any of the vaccines are going to give you good protection against serious illness and death.

This is real time science. We have to wait and see what happens, scientists can't magic up evidence from the future out of their arse.

Also, antibody blood tests as evidence of immunity is only part of the immunity story.

@Underparmummy

This is real time science. We have to wait and see what happens, scientists can't magic up evidence from the future out of their arse.

Also, antibody blood tests as evidence of immunity is only part of the immunity story.

Agree, it will take time before we can look back to assess the best overall vaccination approach - all have pros and cons.

What will really matter is having properly disaggregated data to ensure we have the best options for each group be that age, sex, race or pre existing condition.