Covid-19 vaccines and vaccinations

Discussion in 'Epidemics (including Covid-19, not Long Covid)' started by hinterland, Dec 3, 2020.

  1. lunarainbows

    lunarainbows Senior Member (Voting Rights)

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    Last edited: May 22, 2021
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  2. lunarainbows

    lunarainbows Senior Member (Voting Rights)

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    Sorry I wanted to tag @Snow Leopard in the above to get your thoughts as well.
     
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  3. Snow Leopard

    Snow Leopard Senior Member (Voting Rights)

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    Maybe. I can't find the latest PHE data. The claim is likely to be based on retrospective estimates of infection comparing for a non-randomised (and thus biased) non vaccinated vs. the vaccinated cohort for those who showed up at a testing clinic or hospital and tested positive (I'd wager almost all were symptomatic).

    But I'm not sure about how conclusive the data is, the numbers particularly for the indian variant might be too low to be generalised. I note that other reports on the recent PHE data stated
    https://news.yahoo.com/uk-analysis-finds-two-doses-132225350.html

    Of course your individual risk can differ from the quoted figure due to demographic/genetic/etc factors.

    In any event, '80%' should mean people still need to be careful to prevent spread to others, but whether they will is another question. UK daily case numbers have risen slightly since the start of the month.
    https://www.worldometers.info/coronavirus/country/uk/
     
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  4. Mij

    Mij Senior Member (Voting Rights)

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    An infectious disease doctor explained how it's very important to get the surge down in India because it will create new variants that our current vaccines won't protect us from. He compared the differences between Ebola and COVID respiratory-type viruses. and how Ebola deaths were more immediate so it prevented spread, unlike COVID where the virus spreads like wild fire to infect as many people as possible, and that it could put us back to square one.
     
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  5. Wits_End

    Wits_End Senior Member (Voting Rights)

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    The Health Secretary on the news tonight was saying that Pfizer was showing to be 80% effective against symptomatic infection - no mention of variants, I think - and AstraZeneca 60%. The latter was reported as probably being unduly low because of the relative newness of the vaccine and the fact that it had largely been administered to the elderly, where immune response is likely to be less good. It was suggested that the percentage would rise as time went on and it was administered to younger people.

    I also saw something indicating that Pfizer can be stored in a fridge for longer than originally thought, which could be useful.
     
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  6. Wonko

    Wonko Senior Member (Voting Rights)

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    Was he looking dizzy when he said all that?

    He may get specialist training to spin that much and not look dizzy.
     
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  7. Snow Leopard

    Snow Leopard Senior Member (Voting Rights)

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    Here is some data:

    https://twitter.com/user/status/1396220535735046149


    Note the sample sizes are relatively small, meaning the figures are somewhat uncertain.

    The previously reported 80% claim was based on combined AZ/Pfizer results...
     
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  8. Snow Leopard

    Snow Leopard Senior Member (Voting Rights)

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    By the way, it is being claimed that the recent PHE AstraZeneca data may be an 'underestimate' as many of those who contracted COVID had only had their booster within 2-4 weeks of contracting COVID and therefore they may not have had enough time to develop 'full immunity'.

    That claim is not science-based! You'd actually expect maximal protection at 2-4 weeks after the booster shot!

    The phase 1/2 Oxford data, showed that antibody titres peaked at around 2 weeks after the booster shot and then started to decline!
    https://www.nature.com/articles/s41591-020-01179-4

    This is typical of antibody titre kinetics post-booster shot!
    https://www.researchgate.net/public...on-The-kinetics-of-B-cell-activation_W640.jpg
     
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  9. MeSci

    MeSci Senior Member (Voting Rights)

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    I think it was decided not to administer AstraZeneca to people under a certain age. Not 100% sure.
     
    Last edited: May 23, 2021
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  10. JemPD

    JemPD Senior Member (Voting Rights)

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    yes @MeSci in uk it was, due to clot risk. I think to under 30s, but may have been under 40s i cant remember
     
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  11. Saz94

    Saz94 Senior Member (Voting Rights)

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    Sadly no.

    I’m not sure I understand the specifics, but my understanding is that here has been a lot of poor data analysis recently.

    Dr Deepti Gurdasani, an epidemiologist, has been posting her analyses on Twitter and they’re very helpful. I will try to find the relevant thread for you.

    The good news for you is that levels of COVID infections estimated by Zoe are currently pretty low in both Croydon and Kingston.
     
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  12. Saz94

    Saz94 Senior Member (Voting Rights)

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    Sorry, on second thoughts I don’t have the energy to find the relevant thread from Dr Gurdasani for you, but hopefully somebody else here can.
     
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  13. Snow Leopard

    Snow Leopard Senior Member (Voting Rights)

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    @Jonathan Edwards
    Have you seen this?

    https://www.researchsquare.com/article/rs-558954/v1

    I think the title is extremely misleading since no evidence of mimicry has been provided and a study already ruled out molecular mimicry due to the spike protein.

    I have previously proposed penton-heparan sulfate/pf4 or spike-heparan sulfate/pf4 B-cell cocapture as a mechanism (on Twitter), but of course no one cares what I have to say.

    Yet the data suggesting the increased risk of splice variants of the spike protein leading to increased secreted spike protein could be a key risk factor, but this is only suggestive evidence.
     
    Last edited: May 27, 2021
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  14. Wits_End

    Wits_End Senior Member (Voting Rights)

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  15. Snow Leopard

    Snow Leopard Senior Member (Voting Rights)

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  16. Wits_End

    Wits_End Senior Member (Voting Rights)

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    Ah, sorry, I didn't recognise the similarities from what you wrote.
     
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  17. Mij

    Mij Senior Member (Voting Rights)

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    Health Canada is extending the expiration date of AZ vaccine from May 31 to July 1 :emoji_thinking:
     
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  18. Wonko

    Wonko Senior Member (Voting Rights)

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    Whether or not that is a good idea depends on when they acquired them - AZ state a maximum lifespan of 6 months.

    If they are pushing it beyond that fairly simple requirement then who is to say if they are following the other storage rules? All equally simple on paper, but in practice probably more difficult.

    I would have thought that before making the decision to 'extend' the lifespan they should of at least assessed AZ vaccine that is older than recommended to determine it's viability, and toxicity.

    Does Canada even have the facilities to do this, given they are, as far as I am aware, importing all of it, and this implies they may not have the facilities to do such testing.

    (6 months is quite a long time to have unused vaccine lying around when/if there is a demand for it - it should be long enough to use it up, given staged delivery etc. Quite why they would have AZ vaccine hanging around longer than that is puzzling)
     
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  19. Mij

    Mij Senior Member (Voting Rights)

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    @Wonko

    There are 45,000 vaccines set to expire May 31. There was a pause because of blood clots.

    They have not distributed them to primary care doctors who have been screaming that they want them for months. Some vaccines were only distributed to pharmacies this past Friday.

    Health Canada said that they are 'stable'. Whatever that means.
     
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  20. Milo

    Milo Senior Member (Voting Rights)

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