Antibodies from former COVID patients
neutralise Delta, Omicron An international research team, led by Tel Aviv University, has demonstrated that antibodies isolated from the immune system of recovered COVID-19 patients are effective in neutralising all known strains of the virus, including the Delta and Omicron variants. Published in the journal Communications Biology, the discovery may eliminate the need for repeated booster vaccinations and strengthen the immune system of populations at risk.
T
place where the spike binds the cellular receptor
According to Freund, the effectiveness of these
ACE2. Of course, we were not the only ones to
antibodies might be related to the evolution of the
isolate these antibodies, and the global health
virus. She explained, “The infectivity of the virus
system made extensive use of them until the arrival
increased with each variant because each time, it
he work is a continuation of a preliminary
of the different variants of the coronavirus, which
changed the amino acid sequence of the part of
study conducted in October 2020, at the height of
in fact rendered most of those antibodies useless.
the spike protein that binds to the ACE2 receptor,
the COVID-19 crisis. At that time, Tel Aviv’s Dr
“In the current study, we proved that two
thereby increasing its infectivity and at the same
Natalia Freund and colleagues sequenced all the
other antibodies, TAU-1109 and TAU-2310,
time evading the natural antibodies that were
B immune system cells from the blood of people
which bind the viral spike protein in a different
created following vaccinations. In contrast, the
who had recovered from the original COVID
area from the region where most of the antibodies
antibodies TAU-1109 and TAU-2310 don’t bind
strain in Israel and isolated nine antibodies that the
were concentrated until now (and were therefore
to the ACE2 receptor binding site, but to another
patients produced. The researchers have now found
less effective in neutralising the original strain),
region of the spike protein — an area of the viral
that some of these antibodies are very effective in
are actually very effective in neutralising the Delta
spike that for some reason does not undergo many
neutralising the Delta and Omicron variants.
and Omicron variants. According to our findings,
mutations — and they are therefore effective in
“In the previous study, we showed that the
the effectiveness of the first antibody, TAU-1109,
neutralising more viral variants.”
various antibodies that are formed in response
in neutralising the Omicron strain is 92%, and in
The two antibodies, cloned in Freund’s
to infection with the original virus are directed
neutralising the Delta strain, 90%. The second
laboratory at Tel Aviv University, were sent
against different sites of the virus,” Freund said.
antibody, TAU-2310, neutralises the Omicron
for tests to check their effectiveness against live
“The most effective antibodies were those that
variant with an efficacy of 84%, and the Delta
viruses in laboratory cultures at the University of
bound to the virus’s ‘spike’ protein, in the same
variant with an efficacy of 97%.”
California San Diego and against pseudoviruses
30 | LAB+LIFE SCIENTIST - Oct/Nov 2022
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