First in vivo data from Washington University show EVUSHELD reduces viral burden of all tested Omicron subvariants in the lungs

WILMINGTON, DE, USA I March 21, 2022 I New preclinical authentic ‘live’ virus data from Washington University School of Medicine demonstrated that EVUSHELDTM (tixagevimab co-packaged with cilgavimab) retains potent neutralizing activity against the emerging and highly transmissible Omicron SARS-CoV-2 BA.2 subvariant.1 The data also showed that EVUSHELD retains activity against Omicron BA.1 and BA.1.1.1

In addition, in vivo (live organism) data generated using mice infected with Omicron BA.1, BA.1.1 and BA.2 demonstrated that EVUSHELD significantly reduced the viral burden and limited inflammation in the lungs for all three subvariants.1 SARS-CoV-2 viral load is associated with increased disease severity and mortality as well as post-COVID conditions (long COVID).2,3

The study used a transgenic mouse model to evaluate EVUSHELD in pre-exposure prophylaxis (prevention) of COVID-19, similar to how EVUSHELD is used in the clinic. These are the first in vivo data evaluating EVUSHELD’s efficacy against the Omicron variants versus previous in vitro neutralizing activity assays in cultured cells.

The Washington University findings were reported online on bioRxiv, a preprint server.

Michael S. Diamond, MD, PhD, The Herbert S. Gasser Professor, Departments of Medicine, Molecular Microbiology, Pathology & Immunology, Washington University, US, said: “These new in vivo mouse model data confirm previous in vitro neutralization activity results for EVUSHELD against Omicron. The findings demonstrate that EVUSHELD was effective at protecting against infection in the lungs, a critical disease site for severe COVID-19, across all Omicron subvariants tested.”

John Perez, Senior Vice President, Head of Late Development, Vaccines & Immune Therapies, AstraZeneca, said: “These important data show that EVUSHELD reduced viral burden and limited inflammation caused by Omicron. The findings further support EVUSHELD as a potential important option to help protect vulnerable patients such as the immunocompromised who could face poor outcomes if they were to become infected with COVID-19.”

Additional ‘live’ virus data from Aix-Marseilles University and pseudovirus data from the US Food and Drug Administration also demonstrated that EVUSHELD neutralizes BA.2.4,5 According to the World Health Organization, cases of BA.2 have been identified in 85 countries to date, with prevalence increasing in several parts of the world.6

EVUSHELD is authorized for pre-exposure prophylaxis (prevention) of COVID-19 in the US and several other countries. EVUSHELD is intended for vulnerable populations who have a medical condition or are receiving immunosuppressive medications or treatments and may not mount an adequate immune response to COVID-19 vaccination, as well as those individuals for whom COVID-19 vaccination is not recommended.

EVUSHELD is authorized only for the duration of the declaration that circumstances exist justifying the authorization of the emergency use of EVUSHELD under Section 564(b)(1) of the Food, Drug and Cosmetic Act, 21 U.S.C. § 360bbb-3(b)(1), unless the authorization is terminated or revoked sooner.

Visit to learn more.

About AstraZeneca
AstraZeneca is a global, science-led biopharmaceutical company that focuses on the discovery, development and commercialization of prescription medicines in Oncology, Rare Diseases and BioPharmaceuticals, including Cardiovascular, Renal & Metabolism, and Respiratory & Immunology. Based in Cambridge, UK, AstraZeneca operates in over 100 countries, and its innovative medicines are used by millions of patients worldwide. For more information, please visit and follow us on Twitter @AstraZenecaUS.


  1. Case, J et al. Resilience of S309 and AZD7442 monoclonal antibody treatments against infection by SARS-CoV-2 Omicron lineage strains. Available at [Last accessed March 2022]
  2. Fajnzylber, J et al. SARS-CoV-2 viral load is associated with increased disease severity and mortality. Available at [Last accessed March 2022}
  3. Su Y, et al. Multiple early factors anticipate post-acute COVID-19 sequelae. Cell. 2022;185(5):881-895.e20.
  4. FACT SHEET FOR HEALTHCARE PROVIDERS: EMERGENCY USE AUTHORIZATION FOR EVUSHELD™ (tixagevimab co-packaged with cilgavimab). Available at: [Last accessed: March 2022].
  5. Zhou H, et al. Neutralization of SARS-CoV-2 Omicron BA.2 by Therapeutic Monoclonal Antibodies. Available at: [Last accessed March 2022].
  6. World Health Organization. Weekly epidemiological update on COVID-19 – 22 February 2022. Available from:—22-february-2022 [Last accessed: March 2022].
  7. Dong J, et al. Genetic and structural basis for recognition of SARS-CoV-2 spike protein by a two-antibody cocktail. bioRxiv. 2021; doi: 10.1101/2021.01.27.428529.
  8. Robbie GJ, et al. A novel investigational Fc-modified humanized monoclonal antibody, motavizumab-YTE, has an extended half-life in healthy adults. Antimicrob Agents Chemother. 2013; 57 (12): 6147-53.
  9. Griffin MP, et al. Safety, tolerability, and pharmacokinetics of MEDI8897, the respiratory syncytial virus prefusion F-targeting monoclonal antibody with an extended half-life, in healthy adults. Antimicrob Agents Chemother. 2017; 61(3): e01714-16.
  10. Domachowske JB, et al. Safety, tolerability and pharmacokinetics of MEDI8897, an extended half-life single-dose respiratory syncytial virus prefusion F-targeting monoclonal antibody administered as a single dose to healthy preterm infants. Pediatr Infect Dis J. 2018; 37(9): 886-892.
  11. AstraZeneca news release. New analyses of two AZD7442 COVID-19 trials in high-risk populations confirm robust efficacy and long-term prevention. Available at: [Last accessed: March 2022].
  12. van Erp EA, et al. Fc-mediated antibody effector functions during respiratory syncytial virus infection and disease. Front Immunol. 2019; 10: 548.
  13. Harpaz et al. Prevalence of immunosuppression among US adults, 2013. JAMA. 2016 Dec 20;316(23):2547-2548. Available at:
  14. AstraZeneca data on file.

SOURCE: AstraZeneca