In a recent study, researchers from Karolinska Institutet in Sweden, and others, have characterised the brand new omicron variant BA.2.75, comparing its ability to evade antibodies against current and former variants. The study, published within the journal The Lancet Infectious Diseases, suggests that BA.2.75 shouldn’t be more proof against antibodies than the currently dominating BA.5, which is positive news.

In May 2022, a latest variant of omicron, BA.2.75, was detected, which is driving a wave of infections in India, and has spread internationally. In the previous couple of weeks, BA.2.75 has also been detected in Sweden.

“Identifying how vulnerable the population is, immediately, to emerging variants is crucial,” says Daniel Sheward, researcher on the Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, and the study’s first creator. “By producing a pseudovirus for BA.2.75, we were in a position to test its sensitivity to antibodies present in blood donors.”

Tests were carried out using 40 random blood samples taken in Stockholm, each before and after the primary omicron wave.

“Our study shows that omicron BA.2.75 has roughly the identical level of resistance to antibodies because the dominant variant BA.5, which is reassuring news if we were to suffer a BA.2.75 wave in Sweden”, says Ben Murrell, assistant professor on the Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, and the study’s senior creator.

The researchers from Karolinska Institutet, University of Cape Town, South Africa, ETH Zürich, Switzerland, Karolinska University Hospital, and Imperial College London, Great Britain, have also investigated whether antiviral monoclonal antibodies, that are used clinically to treat already infected patients, lose their effect against omicron BA.2.75, in comparison with BA.5. Here, too, the researchers found no alarming differences.

Ben Murrell’s lab will proceed to observe latest mutations which might be arising in omicron sublineages which will undermine vaccines.

The study was funded by the SciLifeLab’s Pandemic Laboratory Preparedness program, the Erling Persson Foundation, the European Union’s Horizon 2020 research and innovation programme. Daniel J. Sheward, Gunilla B. Karlsson Hedestam and Ben Murrell have mental property rights related to antibodies that neutralise omicron variants.

Source:

Journal reference:

“Evasion of neutralising antibodies by Omicron sublineage BA.2.75”. Daniel J. Sheward, Changil Kim, Julian Fischbach, Sandra Muschiol, Roy A. Ehling, Niklas K. Björkström, Gunilla B. Karlsson Hedestam, Sai T. Reddy, Jan Albert, Thomas P. Peacock, Ben Murrell. The Lancet Infectious Diseases, online September 1 2022, doi:10.1101/2022.07.19.500716.