A portion of our immune defense is based on neutralizing antibodies produced by immune system cells following vaccination or infection. These antibodies bind to the SARS-CoV-2 spike protein, preventing the virus from entering human cells. This mechanism is also known as neutralisation.

Since May of this year, EG.5, as well as its descendent EG.5.1, has been on the increase in several countries. The lineage is also known as Eris and is categorized as a “Variant of Interest” by the World Health Organization (WHO). The study discovered evidence that a greater ability to evade antibodies is the likely source of Eris’s increased spread.

EG.5.1’s Neutralization and Impacts on Immunity

“We found that, in comparison to other currently circulating SARS-CoV-2 lineages, EG.5.1 does not possess an advantage in infecting host cells,” said Lu Zhang, the lead author of the study. “However, further investigations revealed that EG.5.1 is less effectively neutralised by antibodies present in the blood of vaccinated individuals or vaccinated and infected individuals,” Zhang said.

For safety reasons, the studies were carried out with viruses created in the laboratory, known as pseudoviruses.

“In summary, our results suggest that the spread of EG.5 and its sublineages primarily relies on antibody escape rather than an enhanced ability to infect host cells,” said Markus Hoffmann, lead scientist in the study. “However, the increase in the ability to escape antibodies is rather moderate and by no means sufficient to completely undermine our immunity that has been established through vaccination or prior infection,” Hoffmann added.

References:

1. Parums DV. Editorial: A Rapid Global Increase in COVID-19 is Due to the Emergence of the EG.5 (Eris) Subvariant of Omicron SARS-CoV-2. Med Sci Monit. 2023 Sep 1;29:e942244. doi: 10.12659/MSM.942244. PMID: 37654205; PMCID: PMC10478578.

Source: Medindia