Regeneron Pharmaceuticals Inc said on Tuesday prior analyzes suggested its COVID-19 antibody cocktail, and similar drugs, could have reduced activity against the omicron coronavirus variant.

The drugmaker said analysis shows the individual mutations present in the omicron variant indicate "that there may be reduced neutralization activity of both vaccine-induced and monoclonal antibody conveyed immunity."

Further analyzes are ongoing, the company said, adding that there was no direct data testing omicron's resistance to immunity gained from vaccines and monoclonal antibodies.

The comments follow Moderna Inc's chief executive officer, who said COVID-19 vaccines are unlikely to be as effective against the omicron variant as they have been previously.