Scientists from the University of Tel Aviv have identified and isolated two new antibodies that appeared to have great efficacy against SARS-CoV-2, the virus that causes COVID-19. The team found that the two had a combined neutralization efficacy against all strains – including the currently dominant one – of up to 95 percent.
Antibodies have already been successfully employed in treatments. The most effective ones were those found binding themselves to the cellular receptor ACE2 on the virus’s infamous spike protein. As reported in Communications Biology, scientists found two different antibodies not used before that administered in high concentrations could be a suitable alternative to vaccines, especially for at-risk people. They could even make the need for booster doses a thing of the past.
“In the current study, we proved that two other antibodies, TAU-1109 and TAU-2310, which bind the viral spike protein in a different area from the region where most of the antibodies were concentrated until now (and were therefore less effective in neutralizing the original strain) are actually very effective in neutralizing the Delta and Omicron variants,” research lead Dr Natalia Freund said in a statement.
“According to our findings, the effectiveness of the first antibody, TAU-1109, in neutralizing the Omicron strain is 92%, and in neutralizing the Delta strain, 90%. The second antibody, TAU-2310, neutralizes the Omicron variant with an efficacy of 84%, and the Delta variant with an efficacy of 97%.”
The two antibodies were sent to be tested against viruses cultivated in the lab a the University of California San Diego as well as pseudoviruses in the laboratories of the Faculty of Medicine of Bar-Ilan University. Both tests had the same encouraging results. The team believes that the advantage of these two antibodies comes from not attacking the virus where most other antibodies do, so the different variants remain roughly equally susceptible to TAU-1109 and TAU-2310.
“The infectivity of the virus increased with each variant because each time, it changed the amino acid sequence of the part of the spike protein that binds to the ACE2 receptor, thereby increasing its infectivity and at the same time evading the natural antibodies that were created following vaccinations,” Dr Freund explained.
“In contrast, the antibodies TAU-1109 and TAU-2310 don’t bind to the ACE2 receptor binding site, but to another region of the spike protein – an area of the viral spike that for some reason does not undergo many mutations – and they are therefore effective in neutralizing more viral variants. These findings emerged as we tested all the known COVID strains to date.”