Nation Monoclonal antibodies were ‘doing nothing’ against omicron. That’s why FDA pulled its authorization. January 27, 2022 Karen Weintraub, USA TODAY Comments Off on Monoclonal antibodies were ‘doing nothing’ against omicron. That’s why FDA pulled its authorization. Monoclonal antibodies from drug-makers Regeneron and Eli Lilly have proven ineffective against the omicron variant of COVID-19.