Vaccine and antibody treatment effectiveness blunted by all three
Omicron subvariants

Date:
March 3, 2022
Source:
Columbia University Irving Medical Center
Summary:
A new study finds that COVID vaccines and monoclonal antibody
treatments offer less protection against new Omicron subvariants.



FULL STORY ==========================================================================
Only one currently authorized antibody treatment retains its activity
against all Omicron subvariants, according to new research by scientists
at Columbia University and the University of Hong Kong. The study also
shows that the effectiveness of mRNA vaccines is reduced against all
three subvariants of Omicron.


==========================================================================
The findings were published in Natureon March 2 by David D. Ho, MD,
director of the Aaron Diamond AIDS Research Center and the Clyde'56 and
Helen Wu Professor of Medicine at Columbia University Vagelos College
of Physicians and Surgeons.

Omicron is a highly transmissible variant of SARS-CoV-2 that has caused
the biggest surge in COVID cases so far in many countries. Researchers
have identified three subvariants of Omicron that share 21 mutations in
the spike protein, and named them BA.1, BA.1.1 and BA.2.

When Omicron was first identified in November 2021, the dominant variant
was BA.1. Since December, BA.1 cases have declined, while BA1.1 cases
have risen and now make up around 40% of all Omicron cases sequenced
globally. The BA.2 subvariant currently represents only 10% of all
Omicron cases globally but is increasing in prevalence.

In laboratory experiments, Ho and his team studied the ability of 19
monoclonal antibodies and the sera from individuals immunized with one
of two available mRNA vaccines to neutralize the three known subvariants
of Omicron.

Consistent with their previous study on the BA.1 variant, the researchers observed a similar loss of neutralization activity against BA.1.1
and BA.2 in blood samples from individuals who had received two mRNA
shots. However, the decline in neutralization was less prominent in blood samples from individuals who had received three mRNA shots, reinforcing
the importance of booster shots for sustaining immunity.

In neutralization experiments, all three variants exhibited a strong
resistance to most of the monoclonal antibodies tested. Of 19 antibodies,
17 were ineffective against the BA.2 subvariant. The researchers found
that bebtelovimab, the latest monoclonal antibody to receive FDA Emergency
Use Authorization, is the only currently available antibody therapy that
can adequately treat all three Omicron subvariants.

"The emergence of new variants is narrowing our treatment options
and challenging the effectiveness of our current vaccines," says
Ho. "It is critical that we don't relax prematurely and continue
to devise novel strategies to contain this ever-evolving pathogen." ========================================================================== Story Source: Materials provided by
Columbia_University_Irving_Medical_Center. Note: Content may be edited
for style and length.


========================================================================== Journal Reference:
1. Sho Iketani, Lihong Liu, Yicheng Guo, Liyuan Liu, Jasper F.-W. Chan,
Yiming Huang, Maple Wang, Yang Luo, Jian Yu, Hin Chu, Kenn
K.-H. Chik, Terrence T.-T. Yuen, Michael T. Yin, Magdalena
E. Sobieszczyk, Yaoxing Huang, Kwok-Yung Yuen, Harris H. Wang,
Zizhang Sheng, David D. Ho.

Antibody evasion properties of SARS-CoV-2 Omicron
sublineages. Nature, 2022; DOI: 10.1038/s41586-022-04594-4 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/03/220303125021.htm

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