AstraZeneca approval in the US

@FigNorton: More about risk factors (and quite a different story) in this:

Scientific teams from Germany and Norway found that people who developed the clots after vaccination had produced antibodies that activated their platelets, a blood component involved in clotting. The new reports add extensive details to what the researchers have already stated publicly about the blood disorder.

Younger people appear more susceptible than older ones, but researchers say no preexisting health conditions are known to predispose people to the rare reaction. That is worrisome, they say, because there is no way to tell if an individual is at high risk…

[Giving details from one cohort] One patient had preexisting conditions that affected clotting. During a news briefing on Friday, Dr Andreas Greinacher, an author of the report, said those conditions most likely played only a minor role in the reaction that occurred after vaccination.

My bold.


So I have a feeling children are never going to be getting the AZ vaccine unless they can learn some way to differentiate people with this trait. Thanks again!

We’re using AZ here in Canada and have had no problems so far. No reports of blood clots yet. My wife just got her AZ yesterday.

I wonder if j&j will also have a rare clotting side effect. They are somewhat similar vaccines.

Thank you @Treppenwitz (also @Puzzlegal, @Riemann & @Novelty_Bobble) for some really good and informed comments. Please keep it up. Speaking (unasked) for the almost-lurkers who are following things with interest it is appreciated.

I have found the discussion around the AZ vaccine fascinating, and not a little horrifying. In place of a sober evaluation of risk/reward proportionality it seems that point scoring veiled attacks are preferred. I would like to say that this is surprising, but sadly it isn’t.

At this point the real question is whether AstraZeneca will even apply for approval in the US since there is no plan to use it.

Since the US has contracted for enough mRNA vaccine to cover the whole population, and it seems to be arriving pretty quickly, i rather think we should donate all of “our” J&J and AZ vaccine to Covax. They don’t want to deal with the cold chain requirements of the mRNA vaccines, but they desperately need more vaccine. And we aren’t going to end the pandemic without treating the world.

Sorry for the tangential discussion, but yesterday and this morning there were two TV news reports where the reporters kept referring to the “blood clotting concern in Europe with the Johnson & Johnson vaccine”. In one instance the reporter repeated “Johnson & Johnson” whereas the medical professional he was interviewing kept referring to the AstraZeneca vaccine - but didn’t call out the reporter on the difference.

Anyone else noticing this?

Didn’t see that (I’m in the UK) but there have also been concerns regarding the J&J jab. That’s going to be the case for very many vaccines when we are dealing with such large numbers.
I suspect the TV people just heard “blood clots” and mentally inserted AZ because that is the one that garnered the publicity first.
The J&J issue seems to be in the same risk ballpark as the AZ so nothing to worry about and if you are in a vaccine shortfall situation then it is still best to continue using it.
There was a nice clear piece in the Guardian today by David Spiegelhalter (an excellent statistician for putting things in context) which again lays out the relevant risks in a sober and non-biased way.

There wasn’t any attempt at all in that article to rationalize the decision process.

What percentage of young people will get the virus
What percentage of that group will die from the virus

  • vs -
    What percentage who get the vaccine will die from CVST

The links to the relevant information are in the article.

What figures do you have? what rationalisation are you presenting?

then the person writing the article shouldn’t have a problem using them to calculate the risk.

I’m not the one who wrote the article nor am I making a prediction. You claimed it represented the relevant risks involved. I don’t see any attempt in the article to calculate that risk.

What is it you think the article is saying?

What the hell are you talking about? it summarises the relative risks right there in the article, it also provides a link to the detailed figures which can be seen here. look at the very first table

What else are you looking for?

The article that is titled " How big are the blood-clot risks of the AstraZeneca jab?" Well christ knows I suppose. If only it weren’t so damn cryptic perhaps we’d know what it is saying.

The Winton Centre link (“which can be seen here”) is interesting. (Mea culpa, I missed that in the Guardian article, as it looks like that link describes who they are (when in fact it takes you to an article by them) so I skipped it.)

It has limitations because they have to make assumptions to base their calculations on, but I like that it highlights how relative risk (clots vs severe COVID) varies with age (though I can’t see how they can have a good handle on blood clot risks by age cut, based on the relatively small number of reports available. But anyway.)

What I wanted to add was this: you really need to have similar data on severe adverse events for other vaccines in order to make meaningful judgments about how much you should worry about blood clots. For example, lets say the thing you really need to worry about with the Pfizer vaccine is anaphylaxis. If that was really rare in under 30s, rarer than blood clots with AZ (or at least easy to manage if it does occur) then it makes sense to vaccinate under 30s with Pfizer instead of AZ. This sort of data isn’t present in the Winton link, which is really frustrating. As the UK Govt is nudging towards recommending mRNA vaccines for under 30s, I guess this calculation may have been done - but not made public.

As I said upthread, the risk/benefit of a medicine is a relative concept - it depends on the group of patients you’re considering (age under 30s in this case); and the relative risk of alternative treatments within this patient group. It may be that AZ is a relatively bad bet for a 25 year old (because of a better alternative for them), but a much better bet for a 65 year old.

(We would also have to consider the relative risk of anaphylaxis with Pfizer in other age groups; other serious adverse events of the different vaccines within age groups; and, in the current situation of limited supply, the overall value of prioritizing certain vaccines for certain groups. But hey, I was just trying to illustrate a principle here.)


probabilities applied to mortality.

This is what people who are reluctant (about the vaccine) want to see.

Guess so

U.S. Seeks to Pause J&J Covid-19 Vaccine Use Amid Clotting Reports U.S. Seeks to Pause J&J Covid-19 Vaccine Use Amid Clotting Reports - WSJ

this gives new meaning to the “one and done” vaccines.

Of the people I’ve asked who have put off the vaccine the singular answer (paraphrased) is that they don’t want to be a beta tester. They need to get ahead of this for the countries that are behind on vaccinations.

For what appears to be literally a 1 in a million risk, it seems like an over-reaction. I take an estrogen supplement that I believe has a higher risk of serious clots, and I knew that when I decided to start taking it.

Does that include a chance of brain clots or is it DVTs?

Apologies if this information is upthread and I’ve missed it … but I’ve read many times that those who got blood clots from the Astra-Zeneca vaccine have been “mostly women”. I don’t know, though, if that’s more like “95% women” or “55% women”. Have firm numbers been published?

With the J&J vaccine in the U.S., all six people who developed blood clots have been women, and I believe all pre-menopausal (the oldest of the six being still in her 40s).