Οι ήδη πιστοποιημένες
μεταλλάξεις των στελεχών (B1.1.7/501Y.V1), (501Y.V2) (B1.1.28/501.V3) του κορωνοϊού SARS-Cov-2 (Covid-19) σε:
– Αγγλία,
– Νότια Αφρική, και
– Βραζιλία αντίστοιχα,
ΠΡΟΚΑΛΟΥΝΤΑΙ, σύμφωνα με την
προδημοσίευση της συγκλονιστικής μελέτης των Πανεπιστημίων Ροκφέλλερ, Βηθεσδά και
Caltech των ΗΠΑ, από το εμβόλιο BNT162b2 με την εμπορική ονομασία Comirnaty των
Pfizer/BionTech (που είναι «γενετικά
τροποποιημένος οργανισμός»).
Επί κεφαλής της μεγάλης
ομάδας ερευνητών είναι η κ. Θεοδώρα Χατζηιωάννου.
ΠΗΓΗ: Η πειραματική αυτή μελέτη
των Zijun Wang, Fabian Schmidt, Yiska Weisblum,
Frauke Muecksch,
Christopher O. Barnes, Shlomo
Finkin, Dennis
Schaefer–Babajew, Melissa Cipolla, Christian Gaebler, Jenna A. Lieberman, Zhi Yang, Morgan
E. Abernathy, Kathryn E. Huey–Tubman, Arlene Hurley, Martina Turroja, Kamille A. West, Kristie
Gordon, Katrina
G. Millard, Victor Ramos, Justin Da Silva, Jianliang Xu, Robert A. Colbert, Roshni
Patel, Juan Dizon, Cecille
Unson–O’Brien, Irina
Shimeliovich, Anna Gazumyan, Marina
Caskey, Pamela
J. Bjorkman, Rafael Casellas,
Theodora Hatziioannou,
Paul D. Bieniasz, Michel
C. Nussenzweig «Αντισώματα που προκαλούνται από
εμβόλιο mRNA έναντι SARS–CoV-2 και κυκλοφορούσες παραλλαγές» / «mRNA vaccine–elicited antibodies to SARS–CoV-2 and circulating variants», doi: https://doi.org/10.1101/2021.01.15.426911 στο biorxiv, 19.1.2020. ΑΡΧΕΙΟΝ
ΠΟΛΙΤΙΣΜΟΥ, 26.1.2020.
ΠΕΡΙΣΣΟΤΕΡΑ για τον ΚΟΡΩΝΟΪΟ, ΕΔΩ.
To date severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has
infected nearly 100 million individuals resulting in over two million deaths.
Many vaccines are being deployed to prevent coronavirus disease-2019 (COVID-19)
including two novel mRNA-based vaccines1,2. These vaccines elicit neutralizing
antibodies and appear to be safe and effective, but the precise nature of the
elicited antibodies is not known3–5. Here we report on the antibody and memory
B cell responses in a cohort of 20 volunteers who received either the Moderna
(mRNA-1273) or Pfizer-BioNTech (BNT162b2) vaccines. Consistent with prior
reports, 8 weeks after the second vaccine injection volunteers showed high
levels of IgM, and IgG anti-SARS-CoV-2 spike protein (S), receptor binding
domain (RBD) binding titers3,5. Moreover, the plasma neutralizing activity, and
the relative numbers of RBD-specific memory B cells were equivalent to
individuals who recovered from natural infection6,7. However, activity against
SARS-CoV-2 variants encoding E484K or N501Y or the K417N:E484K:N501Y
combination was reduced by a small but significant margin. Consistent with
these findings, vaccine-elicited monoclonal antibodies (mAbs) potently
neutralize SARS-CoV-2, targeting a number of different RBD epitopes epitopes in
common with mAbs isolated from infected donors. Structural analyses of mAbs
complexed with S trimer suggest that vaccine- and virus-encoded S adopts
similar conformations to induce equivalent anti-RBD antibodies. However,
neutralization by 14 of the 17 most potent mAbs tested was reduced or abolished
by either K417N, or E484K, or N501Y mutations. Notably, the same mutations were
selected when recombinant vesicular stomatitis virus (rVSV)/SARS-CoV-2 S was
cultured in the presence of the vaccine elicited mAbs. Taken together the
results suggest that the monoclonal antibodies in clinical use should be tested
against newly arising variants, and that mRNA vaccines may need to be updated
periodically to avoid potential loss of clinical efficacy.
Between 19 October 2020 and 15 January 2021, 20 volunteers who received
two doses of the Moderna (n=14) or Pfizer-BioNTech mRNA (n=6) vaccines were
recruited for blood donation and analyzed. Ages of the analyzed volunteers
ranged from 29-69 years (median 43); 12 (60%) were male and 8 (40%) female. 16
participants identified as Caucasian, 2 as Hispanic, and 1 as African American
or Asian, respectively. The time from the second vaccination to sample
collection varied between 3-14 weeks with an average of 8 weeks. None of the
volunteers had a history of prior SARS-CoV-2 infection and none experienced
serious adverse events after vaccination (Extended Data Table 1).
