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U.S. Department of Health and Human Services

Important Update

ASPR pauses allocation of bamlanivimab and etesevimab together, etesevimab alone, and REGEN-COV 

December 23, 2021

Monoclonal Antibody Therapeutic Updates

The following statement has been updated by our announcement on December 29, 2021 and December 31, 2021

The COVID-19 pandemic is rapidly evolving, and new updates are issued frequently. To view a full list of HHS/ASPR’s updates related to COVID-19 monoclonal antibody therapeutics, please see our full list of updates.

The Assistant Secretary for Preparedness and Response (ASPR) and the Food and Drug Administration (FDA) within the U.S. Department of Health and Human Services are committed to ensuring timely and transparent communication regarding the monoclonal antibody therapies that are currently authorized for emergency use in response to the COVID-19 pandemic.

Circulating SARS-CoV-2 viral variants, including Omicron, may be associated with resistance to monoclonal antibodies. Health care providers should review the Antiviral Resistance information in the Healthcare Provider Fact Sheet for each authorized therapeutic for details regarding specific variants and resistance. The Centers for Disease Control and Prevention (CDC) publishes information about circulating variants in the United States by region. The frequency of the Omicron variant is increasing throughout the U.S. and health care providers should refer to these frequency data as they choose a therapeutic option for their patients.

FDA updated the Health Care Provider Fact Sheets for bamlanivimab and etesevimab administered together, REGEN-COV, and sotrovimab with specific information regarding expected activity against the Omicron variant (B.1.1.529/BA.1). These data show that it is unlikely that bamlanivimab and etesevimab administered together or REGEN-COV will retain activity against this variant. Based on similar cell culture data currently available, sotrovimab appears to retain activity against the Omicron variant.

Based on this information, ASPR will pause any further allocations of bamlanivimab and etesevimab together, etesevimab alone, and REGEN-COV pending updated data from the CDC. Shipments of sotrovimab did resume this week, and delivery of 55,000 doses of product has begun. An additional 300,000 doses of sotrovimab will be available for distribution in January.

The situation varies in different geographic regions and different health care facilities, and there may be circumstances, such as lower frequency of Omicron in a region and limited supply of alternative treatment options, in which the use of existing site supply of these therapeutics is clinically appropriate. We are working to make available the most updated information to health care providers and provide them with appropriate flexibility to provide the best care for their patients. As additional data become available, we will provide updates and further recommendations and consider if additional actions are warranted. 

ASPR and FDA will continue to work with the CDC and the National Institutes of Health on surveillance of variants that may impact the use of the monoclonal antibody therapies authorized for emergency use. We will provide further updates and consider additional action as new information becomes available.

Information on the authorized products for the treatment of mild-to-moderate coronavirus and other authorized products for treatment or prevention of COVID 19 are available on FDA’s Emergency Use Authorization Drugs and Non-Vaccine Biological Products webpage.

Please contact COVID19Therapeutics@hhs.gov with any questions.



  • This page last reviewed: December 31, 2021