Delta breakthrough infection generates broad neutralizing antibody
response in double vaccinated individuals

Date:
March 17, 2022
Source:
American Society for Microbiology
Summary:
A delta breakthrough infection generates a potent and broad
neutralizing antibody response to SARS-CoV-2 in double vaccinated
individuals, according to new research.



FULL STORY ==========================================================================
A delta breakthrough infection generates a potent and broad neutralizing antibody response in double vaccinated individuals, according to new
research.

The findings were published this week in mBio, an open-access journal
of the American Society for Microbiology.


==========================================================================
In the new study, researchers collected sera from individuals attending
St.

Thomas' Hospital in London who tested positive for COVID-19 and had
received 2 doses of either the Pfizer or AstraZeneca vaccines. They
measured how much antibody the person produced and whether the antibodies
were able to prevent infection of cells by different SARS-CoV-2 variants
of concern.

The researchers found that in vaccinated individuals, there was a rapid
and robust IgG recall response following breakthrough infection. This
antibody response had broad neutralizing activity against current
variants of concern, including omicron. The neutralization potency
was 4.5-fold reduced against omicron compared to delta whereas it was
28.9-fold reduced for people who were unvaccinated.

"Overall, a breakthrough infection effectively boosts the vaccine
response, which could provide broad protection against current
variants of concern," said co-author Katie Doores, Ph.D., Reader in
the Department of Infectious Diseases, King's College London, in the
United Kingdom. "Recent studies show a third vaccine dose dramatically increases the neutralizing antibody response, particularly against
omicron. Our data suggests a delta breakthrough infection can also act
as an effective booster. This study provides insights into population
immunity in double COVID-19 vaccinated individuals where SARS-CoV- 2 transmission levels remain high." Dr. Doores said they are now studying
the immune response in more detail by isolating monoclonal antibodies
from individuals experiencing breakthrough infections.


========================================================================== Story Source: Materials provided by
American_Society_for_Microbiology. Note: Content may be edited for style
and length.


========================================================================== Journal Reference:
1. Thomas Lechmere, Luke B. Snell, Carl Graham, Jeffrey Seow, Zayed A.

Shalim, Themoula Charalampous, Adela Alcolea-Medina, Rahul
Batra, Gaia Nebbia, Jonathan D. Edgeworth, Michael H. Malim,
Katie J. Doores. Broad Neutralization of SARS-CoV-2 Variants,
Including Omicron, following Breakthrough Infection with Delta in
COVID-19-Vaccinated Individuals.

mBio, 2022; DOI: 10.1128/mbio.03798-21 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/03/220317111920.htm

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