Sotrovimab and the Omicron Variant

December 22, 2021

Sotrovimab, a COVID-19 monoclonal antibody treatment, was granted EUA in May 2021. The EUA includes mild-to-moderate cases of COVID-19 in those 12+ years of age with a positive COVID-19 test result, who are at high risk of severe COVID-19. Sotrovimab has not been authorized for use in those already hospitalized for COVID-19, or those requiring oxygen therapy due to COVID-19, including higher oxygen rates than administered for a non-Covid-19 related underlying condition.

A medley of monoclonal antibody treatments have been authorized in the battle against COVID-19 – including treatments by Regeneron, Eli Lilly and AstraZeneca. Preliminary laboratory tests have indicated that Sotrovimab performs best against the Omicron variant. This may be due to the fact that Sotrovimab was designed to target a part of the spike protein that hasn’t mutated between previous coronavirus strains and the Omicron variant.

While these experimental results have yet to be peer-reviewed, the U.S. is considering to pause purchasing doses of other monoclonal antibody treatments, and rationing Sotrovimab to states where the prevalence of Omicron is highest. That being said, the concentration necessary for halving viral replication is 3x higher for Omicron than previous strains.