About sotrovimab

Sotrovimab (formerly called VIR-7831) is an antibody that can attack SARS-CoV-2 (the virus that causes COVID-19) and cells in the body that become infected with this virus.

Sotrovimab has been developed by Vir Biotechnology in cooperation with the pharmaceutical company GlaxoSmithKline (GSK). The design for sotrovimab was based on an antibody found in the blood of a survivor of SARS-CoV-1. This virus caused a severe outbreak of pneumonia almost 20 years ago. As SARS-CoV-1 is related to SARS-CoV-2, which is the cause of the current pandemic, sotrovimab can work against both viruses.

Sotrovimab can bind or attach itself to SARS-CoV-2 and a broad range of coronaviruses (and cells that they infect in the body). By binding to SARS-CoV-2, sotrovimab can prevent this virus from infecting cells and turning them into mini-virus factories. Also, sotrovimab can bind to cells of the body that are infected by SARS-CoV-2. By binding to these cells, sotrovimab attracts cells of the immune system, which then destroy the infected cells.

Lab experiments with sotrovimab have found that this antibody is effective against major variants of SARS-CoV-2, including the following:

  • alpha (B.1.1.7)
  • beta (B.1.351)
  • gamma (P.1)
  • delta (B.1.617.2)
  • kappa (B.1.617.1)
  • lambda (C.37)

In Canada

The Canadian government has purchased 10,000 doses of sotrovimab. These have been distributed to Canada’s provinces and territories for use. Patients are not charged for receiving sotrovimab. The drug is administered by intravenous infusion over one hour.

According to GSK Canada, sotrovimab is authorized for the following use: “The treatment of mild-to-moderate COVID-19 confirmed by direct SARS-CoV-2 viral testing, in adults and adolescents (12 years of age and older, weighing at least 40 kg) who are at high risk of progressing to hospitalization and/or death.”

Furthermore, GSK states that sotrovimab has not been authorized for use in the following people:

  • those who are hospitalized due to COVID-19
  • those who require oxygen therapy due to COVID-19
  • those on chronic oxygen therapy due to underlying non-COVID-19-related comorbidity who require an increase in baseline oxygen flow rate due to COVID-19

—Sean R. Hosein


  1. GlaxoSmithKline. Sotrovimab for injection. Product monograph. 14 September 2021.
  2. GlaxoSmithKline. GSK announces purchase agreement with the Government of Canada for COVID-19 monoclonal antibody therapy sotrovimab. Press release. 4 October 2021.
  3. Cathcart AL, Havenar-Daughton C, Lempp FL, et al. The dual function antibodies VIR-7831 and VIR-7832 demonstrate potent in vitro and in vivo activity against SARS-CoV-2. Preprint. 30 September 2021.
  4. Gupta A, Gonzalez-Rojas Y, Juarez E, et al. Early treatment for Covid-19 with SARS-CoV-2 neutralizing antibody sotrovimab. New England Journal of Medicine. 2021; in press.