BCSnob
Middletown, MD
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SARS-CoV-2 Omicron variant escapes neutralization by vaccinated and convalescent sera and therapeutic monoclonal antibodies
MedRxiv Preprint 14Dec2021
Serum samples from several cohorts (no more than 20 per) and two antibody drugs were evaluated for neutralization of two pseudo-viruses: Original strain (Wuhan) and Omicron.
Cohorts:
3 months after double BNT162b2 vaccination
convalescent sera collected prior to the emergence of Delta (labeled as due to Alpha)
convalescent sera collected after Delta became dominant
Antibody drug cocktail of imdevimab and casirivimab
Antibody drug sotrovimab
Natural immunity from Alpha yielded a 47.1x reduction in the neutralization of Omicron relative to original strain
Natural immunity from Delta yielded a 17.4x reduction in the neutralization of Omicron relative to original strain
Serum 3months post 2x Pfizer yielded a 27.0x reduction in the neutralization of Omicron relative to original strain
Antibody drug cocktail of imdevimab and casirivimab was essentially ineffective against Omicron
Antibody drug sotrovimab was effective against Omicron
This study is consistent with others on the reduced effectiveness of 2x Pfizer against Omicron. The new data here is the reduction in natural immunity against Omicron, the extent of the reduction is dependent upon which variant provided the natural immunity.
* This post was
edited 12/16/21 11:28am by BCSnob *
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BCSnob
Middletown, MD
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Here is another study evaluating serum (circulating antibodies) for neutralization of omicron and wild type (original strain) pseudoviruses.
Striking Antibody Evasion Manifested by the Omicron Variant of SARS-CoV-2
BioRxiv Preprint 15Dec2021
Serum samples:
10 patients infected spring 2020 (presumably by the original strain)
13 2x Pfizer vaccinees (high titer samples)
12 2x Moderna vaccinees (high titer samples)
9 J&J vaccinees
5 AstraZeneca vaccinees
13 3x Pfizer vaccinees
2 3x Moderna vaccinees
Pseudovirus neutralization results:
convalescent serum: Only 2 samples neutralized Omicron; >32 fold reduction relative to wild type
Pfizer vaccinees: 6 out of 13 neutralized Omicron; >21 fold reduction relative to wild type
Moderna vaccinees: 11 out of 12 neutralized Omicron; >8.1 fold reduction relative to wild type
J&J and AstraZeneca vaccinees: no samples neutralized Omicron
3x Pfizer or Moderna vaccinees: all samples neutralized Omicron; >6.5 fold reduction relative to wild type
The reductions in pseudovirus neutralization measured with serum 2x Pfizer and 2x Moderna vaccinees was confirmed with few samples of these against live virus samples. Of the vaccines, Moderna had the least reduction in neutralization of Omicron relative to the original strain.
Note:
Above I have made the statements "6 out of 13 neutralized". This is somewhat misleading in that I simplified the actual results. The actual results were "neutralization in 6 out of 13 samples was detected with the assay used". It is possible weak neutralization occurred but at a level below what the assay could detect. However, the trends (reduction in neutralization relative to the wild type) are still correct.
* This post was
edited 12/20/21 09:57am by BCSnob *
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silversand
Montreal
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BC Snob:
"Moderna had the least reduction in neutralization of Omicron relative to the original strain".
Super interesting, and bleeding edge. Thanks.
Am I reading this correctly? : .....in the small data sample(s), it appears that 2 moderna doses offered impressive neutralizing ability among the small cohort tested (higher titer) serum?
On edit: a Version 2 of your linked research was released with the supplemental file. Not sure what this means for the Version 1 conclusion(s), if anything?
Silver
2004 Chevy Silverado 2500HD 4x4 6.0L Ext/LB Tow Package 4L80E Michelin AT2s| Outfitter Caribou
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BCSnob
Middletown, MD
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Keep in mind that the serum samples for those vaccinated with Moderna and Pfizer were purposely chosen based upon having high antibody titers; meaning patients that responded well to the vaccines and were likely recently vaccinated.
Based upon the above I wouldn’t characterize 2 doses of Moderna as impressive; there was still a reduction in neutralization of Omicron relative to the wild type (larger reduction than there was for Delta relative to the wild type, it was 2x-3x for serum collected 1 week post 2nd dose link). I would characterize 2 doses of Moderna as less concerning as 2 doses of Pfizer.
However, it is Moderna (relative to Pfizer) responses to VOCs that lead to my decision to stick with Moderna for my booster.
The preprint (full pdf) discusses results listed in supplemental tables which were not present in the initial posting.
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pianotuna
Regina, SK, Canada
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VOC?
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, soon to have SiO2 batteries, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.
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BCSnob
Middletown, MD
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Joined: 02/23/2002
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Variants of concern CDC. WHO
Current VOCs
Alpha
Beta
Gamma
Delta
Omicron
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silversand
Montreal
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Thanks for the further clarification on this research!
We have had Moderna vaccines all along, too.
My decision to "go with Moderna" was based less on its performance (the early efficacy numbers) and more on what I perceived to be the very complicated procedural to prepare Pfizer, and Pfizer's seemingly extremely tight "best by date" as outlined in the Procedure for Preparation and Reconstitution of Pfizer’s COVID-19 Vaccine. Compare Moderna's Dose Preparation, here--> More forgiving thawing and deployment timelines.
However at this juncture, with what we know now about antibody evasion, every research paper I read on Moderna enforces our choice of being vaccinated with Moderna.
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BCSnob
Middletown, MD
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Here is more info on Moderna's performance against several variants.
Durability of mRNA-1273 vaccine–induced antibodies against SARS-CoV-2 variants
SCIENCE 13 Aug 2021 Vol 373, Issue 6561 pp. 1372-1377
side note:
MSD-ECLIA are products we (the biotech co I work for) make in association with the NIH/NIAID/VRC (sorry, more acronyms).
ECLIA; electrochemiluminescence immunoassay
NIH: National Institute of Health
NIAID: National Institute of Allergy and Infectious Diseases
VRC: Vaccine Research Center
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silversand
Montreal
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Thanks, BC, for the research article link. Reading now...
On another front; this may be a clue, using "ex vivo cultures of the respiratory tract", shining light on why Omicron may be of lower disease severity, and why the Omicron infected may transmit much more readily:
HKUMed finds Omicron SARS-CoV-2 can infect faster and better than Delta in human bronchus here-->
*not fully peer reviewed as yet
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MEXICOWANDERER
las peñas, michoacan, mexico
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An article of interest
https://www.medicalnewstoday.com/article........6084351fd4c466034232ee06e493377eac340d6a
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