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Medicine Science

Trigger of Rare Blood Clots In AstraZeneca COVID-19 Vaccine Found (bbc.com) 191

Long-time Slashdot reader tlhIngan writes: The AstraZeneca vaccine, one of the few approved vaccines to fight COVID-19, was under fire earlier this year for causing blood clots. While the vaccine is still approved for use, and is being used, scientists have been working hard to figure out the cause. The main trigger appears to be caused by the immune system mistakenly identifying a blood protein as part of the virus. The AstraZeneca vaccine has viral RNA embedded on a normal cold virus. Platelet factor 4, a blood protein, is attracted to the virus and sticks to it. Sometimes, the immune system thinks the protein on the virus is the virus and attacks it, causing red blood cells to clump on it, creating a blood clot. This is a positive hope in helping figure out who may be susceptible to blood clots caused by the vaccine and to offer an alternative to those allergic to components of the mRNA vaccines.
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Trigger of Rare Blood Clots In AstraZeneca COVID-19 Vaccine Found

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  • The next question would be why this was not observed at all during Phase 3 trial.

    Is it too rare? Or is the Phase 3 trial too small? Or the population of Phase 3 trial not diverse enough?

    • People also just get blood clots at a normal background rate. Maybe it was overlooked or simply the signal too small to detect in the phase 3 trial. I mean, 1 in 1.5m dying is very very small to pick up. I had a blood clot form in my leg recently due to slipping on a step presumably... Â\_(ãf)_/Â
      • But it wasn't 1 in 1.5m for the target population of the problem, younger women.

        • by feedayeen ( 1322473 ) on Thursday December 02, 2021 @04:20AM (#62038637)
          But you're not going to know which populations might be subject to an increased adverse response. It's also not the only potential adverse response that could occur. If you divide your population into a dozen different groupings based on age, gender, health, preexisting conditions and search for a dozen different potential adverse responses, you'd be doing 144 different tests for statistical significance you'd be likely to find something with a P-value under 0.01 while being the product of random sampling.

          Their phase 3 trial had 32,449 people. There would have been a 1 in 50 chance of someone dying in the trial from this condition if the death rate for the overall population is 1 in 1.5 million and both populations where intended to be representative of the normal adult population.

          You're also in a state where delays cost lives. You could ramp trials up more and more, maybe once you're at a few million people a few clear signals like this one. But in that time you're delaying vaccination rates by several more months during a period where we were having 5k to 10k deaths per day between the US and Europe.
    • by Vihai ( 668734 ) on Thursday December 02, 2021 @03:17AM (#62038555) Homepage

      It has an incidence estimated in 4 in a million, thus it was not detected by the phase 3 trials, even if they had a particularly large number of participants (30,000 if I recall correctly).

    • by gweihir ( 88907 )

      Yes, it is too rare. It just showed up because of a lot of vaccinations in a short time and very careful monitoring. With regular vaccination numbers, nobody would ever have noticed, because the rate at which this happens naturally and from other causes would have been a lot hogher.

    • by Rei ( 128717 )

      Too rare. Same with myocarditis. It's impossible to catch very rare events in trials. But it's catching common events that you care the most about. Once a product is approved, there are surveillance systems that then look for very rare events. In the US, VAERS helps raise questions as to whether there's any possible problem areas - although as a self-report system with no curation and no distinguishing between causation vs. random events, it does not answer them on their own. Anything that looks like it mi

    • by ceoyoyo ( 59147 )

      It's too rare. The phase 3s had tens of thousands of people in them. The clotting problem would have required an order of magnitude more people to detect.

      Hemagglutination, which is the proper name for this phenomenon, is something that happens with lots of viruses, including influenza. We don't recognize dying from a blood clot as being a complication of the flu because it's very rare that your immune system reacts this way. We recognize it as a side effect of the AZ vaccine because we are *very* careful wi

  • by eclectro ( 227083 ) on Thursday December 02, 2021 @02:48AM (#62038529)

    There's an old software tech rule that I'm pretty sure comes from writer John Dvorak that he mentioned in an article of his back in the day, in the era Borland existed -

    Never buy a zero

    Being that the first version 1.0 and subsequent major overhauls 2.0 always have a propensity for bugs and errors.

    I'm not exactly sure there's a way to unistall/remove an mRNA vaccine. I'm actually a vaccine proponent but from a scientific perspective it needs to evaluated whether a vaccine can be produced faster than the virus can mutate past the vaccine. The other question that needs to be asked is what results can be obtained by finding solutions to obesity and diabetics - the two comorbidities which causes the most hospitalizations. It might cut hospitalizations by targeting these groups for intervention. Perhaps democrats could also focus on doing something about healthcare now??

    • by gweihir ( 88907 ) on Thursday December 02, 2021 @07:21AM (#62038923)

      I'm not exactly sure there's a way to unistall/remove an mRNA vaccine.

      There is not. (m)RNA gets disposed of by your body after a single use. You cannot uninstall/remove something that is not there anymore.

      • I'm not exactly sure there's a way to unistall/remove an mRNA vaccine.

        There is not. (m)RNA gets disposed of by your body after a single use. You cannot uninstall/remove something that is not there anymore.

        You can't uninstall/remove the immune response created by the vaccine, but that's the case with every vaccine... and, of course, the whole point of vaccination.

    • Re: (Score:2, Funny)

      by Anonymous Coward

      There is a way... you have to puree 6 to 12 carolina reaper peppers and use them as an enema. The carolina reaper is embedded with mRNA attractants that pull the mRNA vaccines out through the lining of your large colon.

      I tired it and now I'm confirmed to have no traces of mRNA in my body. Do your own research, but this is a legit way to remove the mRNA vaccine from your body.

  • ... to that of side effects in other vaccines? Not a loaded question, genuinely don't know and just curious.

    • Are you asking about other side-effects than blood-clots? If so that's an interesting question but if you are only comparing blood-clots as a side-effect then phantomfive answers the question above by referencing the delivery mechanism of a given vaccine.

      • by Viol8 ( 599362 )

        All side effects, if there are any others.

        • Very hard question to answer. We would likely need to set a threshold for "seriousness". Basically if you check out the VAERs data posted by nonBORG, you will see a lot of the reports are headaches, nausea, swelling, redness, and related pain. It's likely very hard to compare these symptoms between the vaccines and most of these are effectively the immune system reacting and the body dealing with that. For instance, diet would affect some of these later effects such as nausea or headaches (e.g. drink more w

        • by gweihir ( 88907 )

          All side effects, if there are any others.

          Then "very, very safe". Also, you always have to take into account effectiveness and risks of what is prevented as well. With that, these vaccines are likely in the top tier for vaccination. The mRNA ones may even be "safest ever" in an overall risk evaluation.

    • by gweihir ( 88907 )

      At this probability, it would be "not identified". The only reason these were identified at all is a huge number of vaccinations combined with very careful monitoring for side-effects. For any other vaccine, nobody would have noticed anything, as blood-cloths form naturally and from other reasons as well and that would have hidden the effect completely at normal vaccination rates.

  • Excellent (Score:5, Insightful)

    by gweihir ( 88907 ) on Thursday December 02, 2021 @03:55AM (#62038599)

    So it goes from "very, very safe" to "extremely safe". While getting COVID still is basically on the safety-level of "crapshot".

  • Is there a macro to change "blood clots" to "rare blood clots"?

    We rarely see any reference to vaccine harms without "rare" being added - seemingly, it's automatic.

  • Told ya so time.

    Let me guess... La la la your ears are covered you cant hear me.

    Thought the science was settled? Apologies for FORCING people to take this? Of course not.

    We had to listen to everyone saying people who wanted to wait were wrong.... Now we can't find an audience after it's determined we were right.

    Typical.

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