Fantastic COVID vaccine news from Pfizer today!
Protection for 6 months:
π΅ 91% efficacy overall (850 to 77, placebo vs vaccine)
π΅ ~95-100% efficacy against severe disease
π΅ No safety concerns out to six months, with 44,000 people evaluated
Those are REALLY great numbers! π§΅
No safety concerns, with 12,000 subjects tracked for at least six months after the 2-doses!
44,000 subjects total
For protection against severe COVID out to six months:
π΅ 100% by one definition (CDC definition. 32 to 0, placebo vs vaccine)
π΅ 95% by another definition (FDA definition. 21 to 1)
OUTSTANDING!
Those protection numbers are encouraging signs that protection against COVID cases may last longer than a year with this vaccine. We could make better predictions / projections about durability of vaccine protection once 6 month antibody and T cell data are public.
Pfizer also share data on protection from B.1.351, the variant first seen in South Africa. The numbers are too small to conclude anything, but at least they are encouraging. Out of a small study (800 people), 6 cases of B.1.351 in the placebo vs. 0 in the vaccinated people.
I am thankful for all of that.
β’ β’ β’
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My new MedCram interview in response to the heated discussion π₯ between Senator Rand Paul and Dr. Tony Fauci in the Senate recently on immune memory and immunity to COVID.
With helpful bookmarks!
0:46β Heated exchange between Dr. Fauci and Senator Rand Paul
1:00β How long does immunity last for those whoβve had COVID-19?
3:31β How antibody levels and T cells drop over time
4:03β Dr. Fauci: Difference between in vitro and real-world studies
6:22β Huge variability from person to person for post coronavirus immunity
8:20β Policy decision: individual vs. community goals during a pandemic
10:12β Should mask-wearing continue for those whoβve had COVID-19?
It is good to see this AstraZeneca Oxford ChAdOx COVID vaccine efficacy clinical trial report in America. It will be more valuable to see the FDA filing documents when they are ready. Another COVID vaccine success! π§΅
79% effective at preventing COVID cases. These results are quite similar to AZ COVID vaccine trial results in the UK (which took a long time to deconvolute).
While the AstraZeneca vaccine works, I don't see myself recommending it to anyone who has access to the Pfizer, Moderna, or J&J (1-dose) COVID vaccines. Almost all of the indications are the Pfizer and Moderna 2-dose RNA vaccines protect better (at least over several months).
How much immunity do you need to stop COVID? And what about the variants?
Here's the way I am currently thinking about it. Please imagine these models written in crayon. They are not formal, just where my head is at. π§΅
Immunology is complicated, and scientifically proving all mechanisms of protection in humans is somewhere between hard and impossible. But not to say we know nothing. I summarized the scientific knowledge on immunity to SARS2 in this review last month. doi.org/10.1016/j.cellβ¦
What I have said for the past 20 years (in almost every scientific seminar I give) is:Β
The best vaccine is one that elicits high concentrations of neutralizing antibodies and maintains those high amounts forever.
For any antibody neutralization sensitive pathogen.
The speed of progress to update COVID vaccines is just incredible. Moderna shipped an updated B1351 (South Africa variant) RNA booster vaccine candidate to the American NIH Vaccine Research Center last week for immediate human Phase 1 clinical trial. π§΅
The booster vaccination plan is reasonable, and such a variant booster vaccine could be available quite quickly with an immunogenicity and safety trial.
(/2)
The approach seems likely to elicit high amounts of crossprotective antibodies, based on recent reports of very high antibody responses after 1-dose COVID RNA vaccine immunization of people with previous COVID disease. And the T cell responses will be conserved and boosted.
(/3)
(iv) Durability of immunological protection against COVID-19 is still unknown for each of these vaccines.
(v) The J&J 1-dose does quite well against the SA variant. That's a big deal! In contrast, the AstraZeneca vaccine appears to have almost no efficacy against that variant (~10% efficacy in confirmed cases).
(vi) Lastly, the J&J vaccine had substantial increases in neutralizing antibodies after two doses (T cells were not reported post-boost). nejm.org/doi/full/10.10β¦
The J&J COVID-19 1-dose vaccine data have been filed with the FDA and are under review there (probably final decision tomorrow).
Here are my thoughts on the J&J 1-dose COVID-19 vaccine, now that the data are public.π§΅
(Janssen=J&J = Johnson & Johnson) Vaccine name: Ad26.COV2.S
Executive summary:
π΅ 1-dose. Very convenient! And easy to store.
π΅ Essentially 100% protective against death or hospitalization. Very good!
π΅ 69% protection against symptomatic COVID-19. Just ok.
π΅ Similar protection against the South Africa variant (72%-->64%). Very good!
The FDA EUA package data are consistent with the statements in the J&J vaccine press release several weeks ago.