Fact Check-Monoclonal antibodies limited by FDA are ineffective at treating Omicron

After the United States Food and Drug Administration (FDA) limited the use of some monoclonal antibody COVID-19 treatments due to data showing a reduced effect against the Omicron variant, social media users have falsely claimed the FDA is suppressing an effective treatment for the disease.

On Jan. 24, the FDA revised its emergency use authorization (EUA) for COVID-19 antibody treatments from Regeneron and Eli Lilly to limit their use, given the drugs are unlikely to work against the Omicron variant of the coronavirus (here).

The move prompted social media users to claim that the FDA is withholding vital drugs (here, here, here).

In a video seen at least 63,000 times since being posted to Facebook on Jan. 23, Ultimate Fighting Championship (UFC) president Dana White said (here "Ever since I came out and said what I did, it’s almost impossible now to get monoclonal antibodies. They're making it so you can't get them. Medicine that absolutely works, they're keeping it from us".

While White made the comments on Jan. 15, commenters on the video have used the quote to claim the FDA is lying about the efficacy of monoclonal antibodies against Omicron.

Meanwhile, Florida Governor Ron DeSantis claimed on social media that the Biden Administration “revoked” the EUA for “lifesaving” monoclonal antibody therapies, “without a shred of clinical data to support its decision” (here).

The FDA told Reuters it did not revoke the authorizations but revised them to limit use of the treatment.

Omicron now accounts for more than 99% of all COVID-19 cases in the U.S., according to the Centers for Disease Control and Prevention (CDC), as of Jan. 22, here.

The FDA said in a Jan. 24 statement that monoclonal antibody combinations bamlanivimab/etesevimab and casirivimab/imdevimab (also known as REGEN-COV, Regeneron or Ronapreve) can now only be used when a patient is likely to have been infected with or exposed to a variant that is susceptible to them (here).

Data shows the treatments are “highly unlikely” to be active against Omicron, it said.

The National Institutes of Health (NIH) also updated its COVID-19 treatment guidelines, stating the Omicron variant has “numerous mutations in the spike protein” and is “predicted to have markedly reduced susceptibility” to the therapies (here).

A University of Oxford trial launched in March 2020 found Regeneron’s monoclonal antibody combination reduced the deaths of patients hospitalized with variants of COVID-19 prior to Omicron’s detection (here).

However, the trial’s co-chief investigator Professor Sir Peter Horby, director of the University of Oxford’s Pandemic Sciences Centre, told Reuters that Omicron has rendered many monoclonal antibody treatments “much less effective”.

Prof. Horby pointed Reuters to evidence demonstrating how Omicron has “substantially affected” the two monoclonal antibody combinations.

He said structural (computational) modelling (here), laboratory assays (here, here), and unpublished tests in animal experiments that have data “confirm[ing] inactivity”, show the treatments “will not have significant clinical benefit” against Omicron.

The peer-reviewed laboratory assay study, published in Nature on Jan. 19, assessed the effect of several monoclonal antibodies against the variant, finding Regeneron, Eli Lilly and another combination (Celltrion) showed “an almost complete loss of neutralizing activity” against Omicron (here). Meanwhile, some other monoclonal antibodies retained “substantial inhibitory activity”.

Another peer-reviewed paper shows the sotrovimab monoclonal remains active against Omicron (here).

The NIH confirmed sotrovimab will still be available for high-risk, non-hospitalized patients (here).

The FDA also said that the limited antibody treatments may be re-authorized in certain U.S. regions if patients there are likely to contract a variant that is susceptible (here).


False. Studies show monoclonal antibodies bamlanivimab/etesevimab and casirivimab/imdevimab have a reduced impact in treating Omicron. The FDA said it did not revoke EUAs for the treatments but revised them to limit their use.

This article was produced by the Reuters Fact Check team. Read more about our fact-checking work here.