New Pfizer data - 98.9% effective at preventing death

[doireallyneedaname]

Fabulous!

I wonder how comparable the two groups were; I haven't seen the actual data. But around here at least, the Pfizer was given to the more vulnerable as it was available first, and to HCP, for the same reasons. So those groups might be more likely to be hospitalised either because they are older, or because they might come into more contact with cases and/or higher amounts of virus.

The figures around the deaths/seriously ill statistics might have to do with the way those two figures are measured. Seriously ill will be a measure of people who are actually seriously ill because of Covid. Deaths might be the measure that is widely reported of people who have died 'with' Covid and not necessarily from Covid, and thus might include other groups of ill people who have (for example) picked up covid in hospital where they are being treated for another illness that kills them. I don't know for sure - I don't know where they get the figures from, but it's plausible.

[quote Crumpetycrump]Here’s some amazing vaccine news - and yes Oxford AstraZeneca is more effective at keeping people out of hospital than Pfizer!
news.sky.com/story/covid-19-vaccine-rollout-linked-to-85-and-94-drop-in-coronavirus-hospital-admissions-in-scotland-study-shows-12225532[/quote]
This is fantastic news!

I don't quite understand how they came up with the figures in today's headlines about hospital reductions. Apparently there were just over 8000 people hospitalised in Scotland, and they were somehow compared those who had been vaccinated vs those who hadn't. But surely the numbers in the comparable age/occupation groups to the vaccinated people will be fairly small, because most people in those particular age groups would have been vaccinated, and the ones who aren't vaccinated would be in a different age group/vulnerability category. So what does a figure of 84% or 95% reduction really mean in terms of actual numbers, I wonder?

@ErrolTheDragon

News this morning, stats showing spectacular impact of just the first dose of vaccine on serious illness with AZ outdoing Pfizer though both good (94%/85% respectively). The initial report is just Scotland so a relatively small number.

Covid vaccines - 'spectacular' impact on serious illness www.bbc.co.uk/news/health-56153600

I'm looking forward to the climbdown by all the fuckwits posters who have been stoking fears that the AZ was inferior

@Thimbleberries

Hard to tell without seeing the preprint, but yes, the number of events are small and confidence intervals are quite wide. 85/94% numbers in isolation are not an accurate reflection of the study.

Some of the data is here, but no link to the full study yet:
mobile.twitter.com/EdConwaySky/status/1363806457729343488

Oops, forgot to attach.

[quote CoffeeandCroissant]@Thimbleberries

Hard to tell without seeing the preprint, but yes, the number of events are small and confidence intervals are quite wide. 85/94% numbers in isolation are not an accurate reflection of the study.

Some of the data is here, but no link to the full study yet:
mobile.twitter.com/EdConwaySky/status/1363806457729343488[/quote]
Yes, I am being tongue-in-cheek. But it is no more ridiculous than all the slagging off of the AZ vaccine on the basis that press releases from Pfizer were quoting higher figures for efficacy when comparing different measures.

Some posters are determined to create anxiety and unwilling to listen to anyone who understands the science.

Thanks that is much more useful than the headline figures. Also glad that somewhere in the twitter thread was someone pointing out a caveat that said that the results only looked to be getting worse after 3 weeks because of such small numbers, not because immunity was (necessarily) dropping - i.e., not enough data, rather than bad results.

@MissLucyEyelesbarrow I don't think anyone has said AZ is inferior? Not as good against South African varient but should still stop serious illness. The figures from Israel very encouraging especially after 2 jabs for pfizer.

Is 10-12 weeks the norm between the first and second shots? I'm in the U.S. and it is three weeks here. So happy to get my first one yesterday.

@Thimbleberries I didn't see that comment in the Twitter thread, but yes, whoever said that is correct, the smaller numbers from the longer time periods just mean not enough data yet and we will know more soon as more data becomes available over the coming weeks. All looking positive so far though.

Study protocol: bmjopen.bmj.com/content/10/6/e039097

@DulciUke

Is 10-12 weeks the norm between the first and second shots? I'm in the U.S. and it is three weeks here. So happy to get my first one yesterday.

12 weeks is the recommended period between jabs for the AZ vaccine, supported by their trials. The authorities in the U.K. decided to do the same for Pfizer, in the interests of getting more people to the first stage of immunity quicker. This is controversial but seems on the whole to be working ok.

[quote AxMan76]@MissLucyEyelesbarrow I don't think anyone has said AZ is inferior? Not as good against South African varient but should still stop serious illness. The figures from Israel very encouraging especially after 2 jabs for pfizer.[/quote]
Loads of posters have been saying that. Demanding to know why they can't have the Pfizer. Amplifying misleading stats.

I have nothing at all against the Pfizer vaccine - the early data is really encouraging. But I do not want to see the public put off having the AZ one by people with no understanding of the stats they are quoting.

Full preprint for the Scotland study: drive.google.com/file/d/162PJKbIKUFEjLevf_xZZjmuGmhB2v5jO/view

@DulciUke

Is 10-12 weeks the norm between the first and second shots? I'm in the U.S. and it is three weeks here. So happy to get my first one yesterday.

It is beconibg the norm in a few palces after more research was done.

3 weeks is the usual gap because it is the one used in most research, before a vaccine gets ratified for use. It is as much about convenience as for efficacy.

There is now more data for a longer gap, whatver the precise end result is it will not be that extending the gap reduces efficacy!

I have nothing at all against the Pfizer vaccine - the early data is really encouraging. But I do not want to see the public put off having the AZ one by people with no understanding of the stats they are quoting. Which is the precise reason we all keep on replying, isn't it?

Can't let a bad translation go unchallenged.

@turquoisewaters

Are there any statisticians / data people who can explain why you are more likely to die than be seriously ill

Yes, I don't understand this either

I'm not sure because there's very little information there and no actual numbers, but I imagine the percentages are similar to the way the effectiveness was reported and doesn't reflect the numbers. i.e. in the group of people who died a bigger percentage were vaccinated, than in the group of people who developed serious illness.

So, for instance, if 100 people died and a 1000 people became seriously ill, and the figures were say, 95% effectiveness for death and 99% for serious illness, then that would mean that 5 vaccinated people had died, and 10 vaccinated people had got seriously ill. So although it would look from the percentages as if you were more like to die than get seriously ill that would not be the case. But if the numbers were closer, then you would.

I really wish the numbers were available as well: it would be so much clearer!

Do we know if they prevent transmission yet

The other reason to be delighted at the Pfizer success is that it's large scale proof of a new medical technology. More efficacious vaccines will come from this tech in the future. So it's bigger than whining about not having AZ data!

I'd like to know the difference between how the figures in these charts were obtained, and how/why they are different from the figures also published a day or two ago of a study that was showing effects of 57-70% of reduced hospitalisation (I think) after one dose - I think it was because it was over 80s, but I'm not sure, and I couldn't find a good source comparing the studies. They were definitely not nearly as good as these figures, though!

www.nejm.org/doi/full/10.1056/NEJMoa2101765 I think this is a lot clearer. It gives actual numbers and explains how they did the study. It's not the same results as above as only looking at up to 7 days after the second vaccination, but helpful.

thank you.