Coronavirus Variants and their Impact on Treatment

New coronavirus variants are circulating in the United States. The Department of Health and Human Services (HHS) established a SARS-CoV-2 interagency group (SIG) to improve coordination among government agencies in characterizing and monitoring new variants and determining their potential impact on COVID-19 treatment and prevention measures. The SIG includes the Centers for Disease Control and Prevention (CDC), National Institutes of Health (NIH), US Food and Drug Administration (FDA), Biomedical Advanced Research and Development Authority (BARDA), and Department of Defense (DoD).

They established a classification scheme to describe new strains of the virus as variants of interest, concern, or of high consequence. Three variants of interest, two that were first identified in New York (B.1.526, B.1.525) and one first identified in Brazil (P.2), share a common mutation at D614G and may spread more quickly than viruses without this mutation.1

The CDC is closely monitoring several variants of concern that were first identified in the United Kingdom (B.1.1.7), South Africa (B.1.351), Brazil (P.1), and two variants first identified in California (B.1.427, B.142). These variants may have an impact on diagnostic testing and the efficacy of treatments or vaccines and are associated with increased transmissibility and disease severity compared with earlier coronavirus variants. Currently, no variants of high consequence have been identified.1

Monoclonal antibodies that have received Emergency Use Authorization (EUA) by the FDA—bamlanivimab, bamlanivimab plus etesevimab, and casirivimab plus imdevimab—have shown efficacy in preventing mild-to-moderate COVID-19 from progressing to severe disease in people with certain risk factors.2–7 These treatments are effective against the variant that emerged from the United Kingdom. However, because of concern that bamlanivimab monotherapy is ineffective against the California variants, its distribution in California, Arizona, and Nevada was halted.8 Preclinical data of bamlanivimab with etesevimab show that this combination continues to remain effective against the California variants. This antibody cocktail in addition to the casirivimab and imdevimab combination continue to be available in all states based on their respective EUAs.8

*Since the time of this writing, distribution of bamlanivimab as monotherapy has been halted in all U.S. states.


  1. Centers for Disease Control and Prevention (CDC). SARS-CoV-2 variant classifications and definitions. ( Accessed 3/23/2021.
  2. Bamlanivimab Emergency Use Authorization fact sheet, revised 3/2021. ( Accessed 3/24/2021.
  3. Chen P, Nirula A, Heller B, et al. SARS-CoV-2 neutralizing antibody LY=CoV555 in outpatients with Covid-19. N Engl J Med. 2021;384:229-237.
  4. Bamlanivimab and etesevimab Emergency Use Authorization fact sheet, revised 3/2021. ( Accessed 3/34/2021
  5. Gottlieb RL, Nirula A, Chen P, et al. Effect of bamlanivimab as monotherapy or in combination with etesevimab on viral load in patients with mild to moderate COVID-19: a randomized clinical trial. JAMA. 2021;325:632-644.
  6. Casirivimab and imdevimab Emergency Use Authorization fact sheet, revised 3/2021. ( Accessed 3/24/2021.
  7. Weinreich DM, Sivapalasingam S, Norton T, et al. REGN-COV2, a neutralizing antibody cocktail, in outpatients with Covid-19. N Engl J Med. 2021;384:238-251.
  8. BioSpace. HHS halts bamlanivimab distribution in three states as COVID-19 variants spread. ( Accessed 3/23/2021.
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Updates in the Treatment and Prevention of COVID-19​

Bebtelovimab Is the Only Monoclonal Antibody That Retains Activity Against Omicron Subvariants

The Omicron subvariants BA.2 and BA.2.12.1 now account for 99% of all COVID-19 cases in the United States. Studies assessing the neutralizing activity of monoclonal antibodies for the treatment of COVID-19 have found that only bebtelovimab retains activity against BA.2 and BA.2.12.1. Other monoclonal antibodies, including sotrovimab, bamlanivimab, etesevimab, casirivimab, and imdevimab, are not effective against these new subvariants and are not currently authorized by the US Food and Drug Administration (FDA) to treat COVID-19 due to the high incidence of Omicron BA.2.

Bebtelovimab is authorized for emergency use by the FDA for the treatment of mild-to-moderate COVID-19 in patients 12 years and older weighing at least 40 kg with positive results of direct SARS-CoV-2 viral testing who are at high risk for progression to severe COVID-19, including hospitalization or death. Bebtelovimab should be administered as soon as possible after positive SARS-CoV-2 results and within 7 days of symptom onset.

FDA Approves Baricitinib for Hospitalized COVID-19 Patients

Baricitinib, an oral Janus kinase (JAK) inhibitor, is now FDA-approved for the treatment of COVID-19 in hospitalized adults requiring supplemental oxygen, noninvasive or invasive mechanical ventilation, or extracorporeal membrane oxygenation (ECMO). It is also authorized for emergency use by the FDA for hospitalized pediatric patients between 2 and 18 years of age who require oxygen support. The approval of baricitinib is based on efficacy and safety data from the ACTT-2 and COV-BARRIER clinical trials. In ACTT-2, baricitinib plus remdesivir was superior to remdesivir alone in reducing recovery time, particularly in patients receiving high-flow oxygen or noninvasive ventilation (10 days vs 18 days; rate ratio for recovery, 1.51; 95% confidence interval (CI), 1.10 to 2.08). The 28-day mortality was 5.1% with baricitinib plus remdesivir and 7.8% with remdesivir alone (hazard ratio [HR] for death, 0.65; 95% CI, 0.39 to 1.09). The COV-BARRIER trial found that baricitinib, in addition to standard of care (SoC), was associated with reduced 28-day mortality in hospitalized adults with COVID-19 compared with SoC alone (8% vs 13%; HR, 0.57; 95% CI, 0.41 to 0.78; P= .0018). The 60-day all-cause mortality was 10% with baricitinib plus SoC versus 15% with SoC (P= .005).

Baricitinib fact sheet for healthcare providers. May 2022. (  Accessed 5.24.2022.

Baricitinib (Olumiant®) PI 2022 ( Accessed 5.24.2022.

Bebtelovimab fact sheet for healthcare providers. May 2022. (  Accessed 5.24.2022.

Centers for Disease Control and Prevention (CDC). COVID data tracker. May 23, 2022. ( Accessed 5.24.2022.

Iketani S, et al. Antibody evasion properties of SARS-CoV-2 Omicron sublineages. Nature. 2022;604:553-556.

Kalil AC, et al. Baricitinib plus remdesivir for hospitalized adults with COVID-19. N Engl J Med. 2021;384:795-807.

Marconi VC, et al. Efficacy and safety of baricitinib for the treatment of hospitalised adults with COVID-19 (COV-BARRIER): a randomised, double-blind, parallel-group, placebo-controlled phase 3 trial. Lancet Resp Med. 2021;9:1407-1418.