Astrazeneca dose spacing

[BathroomBuffalo]

Hi all,

I had my first AZ vaccine 5 weeks ago. I am getting texts from my surgery encouraging me to book my second vaccine now, given the rising cases from the Delta varient.

However, the data from the AZ trials seem to show that maximum efficiency is given from dose spacing of about 12 weeks, 83% efficiency at >12 weeks vs 55% at

I waited. But had dose 2 before the restrictions were due to change.

Would depend on how exposed you.are?

Dh hasnt had dose 2 and it's due around mid jul. At the rate of increase it could be 88k cases a day by jul.

I was thinking about this the other day, although it would seem as I had Moderna that i have no choice but to wait the full 12 weeks.

You have various opposing risks.

One AZ jab may only be enough to reduce your risk of hospitalisation with Delta to the same level as that of an unvaccinated person against Alpha. If you were in a situation likely to come into contact with Delta then this is a considerable risk.

NB the above assumes only a 50% risk reduction against a variant over twice as deadly. The actual risk reduction is somewhere between 50 and 90% - being quoted as 70 something %.

BUT - the figures you refer to above are the risk of symptomatic infection - this is one of the first things to go in the event of vaccine weakening. The difference as far as serious illness goes are likely to be far smaller.

In short, if you never want to have covid symptoms and reduce your risk of passing it on to anyone else as far as possible AND you're unlikely to come into contact with the virus until 2 weeks after your booked second jab (e.g. no kids in school, WFH etc) then you may as well wait.
Otherwise you probably want to get that hospitalisation risk down as quickly as possible and an earlier second jab will certainly do that.

Wasn't the 12 week thing changed? I had my first AZ in March, with second jab booked for June but then it was brought forward to May.

Thanks for your comments, very interesting, useful to see the comparison between delta and alpha you make strangeshapedpotato.

I'm as exposed as anyone, two primary school aged children, though I work from home.

Just don't know what to do for the best. Maybe hedge my bets and wait until 9 weeks or so rather than 12?!

I brought mine forward to 9 weeks though I was offered 8 weeks when I went to rebook.

Same reason - hedging my bets!

OP, the risk of you being exposed to Covid if you wait varies considerably according to whereabouts in the country you are. Have you checked the government's interactive map to check Covid rates in your area? If you're in Greater Manchester I wouldn't wait. If you're in rural Devon the decision may be more finely balanced.

My 2nd jab was brought forward slightly and I remember reading about the 12 week efficacy. However, when I booked, I was only offered 2 date options so I had to book it at less than 12 weeks anyway. I imagine if you don't take up your invitation now, you'll keep getting reminders from your GP! I do feel happier knowing I've had 2 jabs now even if they weren't quite 12 weeks apart.

I went for 10 weeks, as it looks like the best results are somewhere between 8 and 12 weeks. I feel the results below 8 weeks aren't enough; whether it then increases regardless of when the second dose is given but even more slowly is hard to know, but you don't yet know if you can get a booster so it's a big decision. It's tough as you're so exposed, but in your position I'd probably wait for 8 weeks.

I’m having mine at 8 weeks. I hope it’s enough of a gap.

Not necessarily as they didn’t do a test at 14 weeks from the first dose of the shorter gap.

I've had mine today at 9 weeks so hedging my bets too!

I think from what I’ve read 8 weeks is the minimum ideal gap. I’ve brought mine forward from 12 because of the whole Delta variant. Just want to be double jabbed now.

I only brought mine forward because of the delta variant. At the moment I’m only 30% covered which isn’t very good. Certainly not worth the reaction I had to it.

So I’m having it done at 8 weeks and hoping that’s ok. Means I’ll be fully protected at the same time as I would have been going for the second jab.

I had mine done at 10 weeks and split the difference! I personally wouldn’t wait until 12 weeks with the current delta situation seeming to really point to 2 doses giving crucial protection. But that’s just me - I’m very risk adverse

I've brought mine forward to 10 weeks, as a compromise. I agree with you, seems silly to rush if the effectiveness is compromised

I'm due my second on monday. I had the option to bring my second forward, but by the time this was possible in my area for my age group, I was already at 9 weeks and I was happy to wait until 12 weeks because that was the day the regs were supposed to relax. I wanted to get max protection as I thought the odds were in my favour with case rates so this was a concious choice. I was under the impression that 10 - 16 weeks was thought of as optimum so was aware of the difference but slightly outside of this wasn't awful.

Then Delta happened. I was slightly more nervous but still didn't think it was worth moving forward at this point as I was so close to 12 weeks.

I do think anyone older than me shouldn't muck about and if they are still only on one dose just bring it forward (I'm 43).

If however, I was younger/had my first dose earlier I would definitely be weighing up the Delta issue depending on where I was and how long I had to go to my second dose. Cases are increasing and 1 dose is only so protective. On balance if I was in my 40s or 30s and still at 7 weeks or below I'd definitely be hoping to bring it forward. If I was at 10 weeks I'd probably wait it out and hope for the best tbh.

We are definitely looking at a third wave so the situation is changing rapidly and in a lot of cases, effectiveness being reduced at 2 weeks slightly goes out the window if the cases of getting covid suddenly shoot up in the next few weeks. You are really then not looking at effectiveness being reduced but effectiveness of 1 dose v effectiveness of 2 doses - its important to see it through this lens.

I have to say at this point, I'm glad I got mine earlier because it made it easier to make the decision and gave me the option to choose. Going forward I think that its going to get increasingly harder to justify waiting longer.

I waited the full 12.

With one jab and having had covid, I reckoned it was worth the gamble.

We're asking people to come in from 8 weeks now.

Thanks for your opinions everyone, some very good points. I've now booked mine for when it will be just over 8 weeks after my first. Will be annoying if I get Covid before then and would wish I'd got the second jab earlier!

I brought mine forward and so meant I had an 8-week gap.

I had this dilemma. Couldn’t see any threads on it, started my own, and have seen loads of similar threads since!

I decided to go for second dose at 9 weeks as we live in Greater Manchester. Anecdotally there seems like a lot of it about here now (3 years out from DC’s primary school last week and one of my DC self isolating as a contact) and I’ve also had to travel locally for work so I think it was the right decision. I probably would have waited for 12 weeks if I lived elsewhere.

I think I read somewhere that AZ is a bit of a slow burner in terms of building immunity so I’m hoping even the slightly less optimal 9 week protection rate might improve as time goes on.