In January, amid the omicron surge, WHO's expert panel recommended GlaxoSmithKline Plc (NYSE:GSK) / Vir Biotechnology Inc (NASDAQ:VIR) and Eli Lilly And Co's (NYSE:LLY) COVID-19 treatments.

• But a new preprint, released late Wednesday night, suggests it may not be possible to use sotrovimab for long. 
• The researchers found that the antibody isn't effective at neutralizing BA.2, the omicron subvariant.
• The preprint prompted Vir to put out a press release early Thursday morning saying their lab analyses suggest sotrovimab "retains neutralizing activity" against BA.2.
• Vir said its preprint would be posted in the "coming week." 
• Notably, in December, the lab found that sotrovimab lost efficacy against a different subvariant of omicron, while a University of Washington lab that works directly with Vir found the opposite.
• Also See: GSK, Vir Biotech File For Emergency Use Nod For Intramuscular Sotrovimab For COVID-19.
• Price Action: VIR shares are down 5.04% at $32.43, GSK shares are up 0.80% at $44.62 during the market session on the last check Thursday.