TWiV 793: COVID-19 clinical update #75 with Dr. Daniel Griffin

August 14, 2021

In COVID-19 clinical update #75, Daniel Griffin reviews vaccine effectiveness against transmission, modeling effectiveness of daily antigen tests, updated CDC guidance for fully vaccinated, risk of infection with time after mRNA vaccination, reduced risk of infection after vaccination, therapeutic anticoagulants in critically ill patients, and 6 month outcomes in hospitalized patients.

Hosts: Daniel Griffin and Vincent Racaniello

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Intro music is by Ronald Jenkees

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4 comments on “TWiV 793: COVID-19 clinical update #75 with Dr. Daniel Griffin

  1. Mr Bear Squash-You-All-Flat Aug 14, 2021

    It is mentioned at 21:25 that the studies show after 6 months, the vaccine effectiveness against infection went from 1.1% to 2.4% (i.e., 2.18x as likely) and was noted as being good news that protection from ‘infection’ (not the key objective of vaccine) hadn’t changed very much. However, when discussing vaccination of people who’ve been naturally infected, it was stated (around 25:00) that there was a 2.34x times higher likelihood of infection for those who’d be naturally infected (but not vaccinated) vs those who’d been vaccinated. If I’ve not misunderstood the above (very possible!), why is a 2x – 2.5x improvement a very meaningful difference in one case and not in the other? I’m not debating the ultimate conclusions here, but the data supporting them seems to conflict.

  2. richard moore MD Aug 14, 2021

    Thank you for your service. But
    Not carbon monoxide monitors.
    We exhale carbon dioxide. (Krebs cycle end product)
    Increase in indoor carbon dioxide reflects air exchange.
    CO2 monitors useful

    The verbal exchange at 38 minutes kind of reminds me of Harry the Hat making change of a $50 bill on the show Cheers.

    Or this British HSE

    Note current World ambient co2 414 ppm.

  3. Bernard B Aug 15, 2021

    Another wonderful presentation. A few things I was unable to follow or don’t seem perfect: That comment on 3-400 people dying a day vs similar deaths per annum. I think you were speaking evocatively. On the one hand, deaths among the vaccinated are running ball park 5% of the unvaccinated. On the other hand, the simulacrum of herd immunity (wretchedly abused concept) that will happen sooner the more people are vaccinated. (Perhaps more likely transition to endemicity rather than “herd immunity.’ Those Dutch numbers are a bit strange and a bit disappointing. Vaccinated case vs unvaccinated household — 71% effective. If the targets in the household are vaccinated results only improve to 75%. One would hope for a multiplicative effect and instead there is not even much of an additive effect. Hard to get a hold of the biological implications.
    The 15 minute criterion seems to have no basis for Delta? Needs more thoughtful update.
    The explanation of the Pfizer effectiveness over time is hard for me to follow. The rate of infections is related to all sorts of environmental factors — behaviours, viral variant mix, and overall rates of infection. How was the data normalized, if it was? Also exactly what sort of test was used — the number does not mean anything to me. Benefits for the previously infected: this is useful data, but does not take into account changing viral populations and other factors. Obviously, with the dynamic viral population, it is hard to nail this down except in a broad backwards looking manner. Of course the data is still useful. In the latter section, the description of 6 categories muffs the statistical meaning of silent infections, folding it into cases. Technically, symptomless is not case even if detected, though the use of this medical term by the medical community is impressively sloppy. But the matter left out and of considerable interest is the question of how many silent infections are there that are Not detected. Unless you were trying to make some point which eludes me. If you have not already done this, how about a take on wearing eyeglasses. The data, such as it is, is very suggestive and the side effects of wearing glasses are minimal There is a fun movie called the President’s analyst where the gimmick, c1970, was a brain implant phone. (Little did they know.) I think this show should be brain implanted, especially in the unvaccinated.

  4. On the latest episodes page the TWIV episodes prior to this Aug. 14 episode are missing.