The Food and Drug Administration (FDA) has revised the Emergency Use Authorization (EUA) for Evusheld (tixagevimab co-packaged with cilgavimab) to increase the initial dose for the preexposure prophylaxis of COVID-19 in certain individuals 12 years of age and older weighing at least 40kg.

Evusheld is a combination of 2 long-acting monoclonal antibodies designed to bind to distinct sites on the SARS-CoV-2 spike protein. Previously, the authorized dose of Evusheld was 150mg of tixagevimab and 150mg of cilgavimab administered as 2 separate consecutive intramuscular injections. 

Under the revised EUA, the FDA has increased the initial authorized dose to 300mg of tixagevimab and 300mg of cilgavimab. The revision was based on recent information indicating that the previously authorized Evusheld dose may be less active against certain Omicron subvariants. A higher dose of Evusheld may be more likely to prevent infection by Omicron subvariants BA.1 and BA.1.1, according to available data.

For patients who have already received the previously authorized dose (150mg of tixagevimab and 150mg of cilgavimab), an additional dose of 150mg of tixagevimab and 150mg of cilgavimab should be administered as soon as possible. Health care professionals should contact eligible patients who received the previously authorized dose to return for an additional dose immediately. The new higher dose will require a larger volume for each injection (3mL instead of 1.5mL) and should be administered to large muscles on the body to accommodate this volume (eg, gluteal muscles).

Evusheld is authorized for individuals who are not currently infected with SARS-CoV-2 and who have not had a known recent exposure to an individual infected with SARS-CoV-2, and:

  • Who have moderate to severe immune compromise due to a medical condition or receipt of immunosuppressive medications or treatments and may not mount an adequate immune response to COVID-19 vaccination; or
  • For whom vaccination with any available COVID-19 vaccine, according to the approved or authorized schedule, is not recommended due to a history of severe adverse reaction (eg, severe allergic reaction) to a COVID-19 vaccine(s) and/or COVID19 vaccine component(s).

At this time, it is unclear what the duration of protection with Evusheld is as the clinical trial data supporting the authorization came before the emergence of the BA.1 and BA1.1 subvariants. As such, the FDA is unable to provide recommendations on the timing of repeat dosing. In a press statement, the Agency noted that updates will be provided when additional data become available.

The revised Fact Sheet for Healthcare Providers can be found here.


  1. FDA authorizes revisions to Evusheld dosing. News release. US Food and Drug Administration. February 24, 2022. Accessed February 25, 2022.
  2. Evusheld fact sheet for health care providers. US Food and Drug Administration. Accessed February 25, 2022.