On 24 February 2022, the Food and Drug Administration (FDA) modified the emergency use authorization (EUA) for Evusheld (tixagevimab co-packaged with cilgavimab) to alter the initial dosage for the authorized usage as pre-exposure prophylaxis/prevention of SARS-CoV-2 in some adults and pediatrics.

According to the recent findings, this long-acting monoclonal antibody (mAB) combination might be less active against specific subvariants of omicron. Furthermore, the available data indicated that a higher dose of Evusheld has a high probability to prevent infection by omicron subvariants BA.1 and BA.1.1 when compared to the originally approved Evusheld dosage.

Earlier, the approved Evusheld dose was 150 mg of cilgavimab and 150 mg of tixagevimab given as 2 different consecutive intramuscular injections, with repeat doses every 6 months while coronavirus remains in circulation. With this EUA revision, the FDA has raised the initial authorized dosage to 300 mg of cilgavimab and 300 mg of tixagevimab. People who have already been administered the previously approved dosage should get an additional dosage of 150 mg of cilgavimab and 150 mg of tixagevimab as early as possible to elevate their mAB levels to those anticipated for people receiving the raised dose.

This long-acting mAB combination is approved for the emergency use as pre-exposure prophylaxis to prevent coronavirus disease in some adults and pediatrics (age twelve years and above weighing at least 40 kg). The medical care personnels must only give it to people who are not currently infected with coronavirus and who were not recently exposed to someone infected with coronavirus. Tixagevimab co-packaged with cilgavimab is only approved for those:

• who are immunocompromised (moderate-to-severe) as a result of a medical condition or who have obtained immunosuppressive medicines or therapies and may not mount an appropriate immune response to SARS-CoV-2 vaccination
• for whom vaccination is not suggested due to a history of serious side effects (like serious allergic reaction) to coronavirus vaccines and/or coronavirus vaccine components.

Evusheld's duration of protection against symptomatic coronavirus infection might not be as long as was illustrated in the clinical trial favoring the initial authorization. This is because the data was assessed from a time period prior to emergence of BA.1.1 and BA.1 subvariants. But, there is no clarity if BA.1 and BA1.1 will still be circulating in the coming months or if another omicron subvariant, BA.2, for which Evusheld is anticipated to have raised neutralizing activity, will become dominant.

People who previously got an initial lower dose of Evusheld must contact medical consultants and come back for an additional dose promptly. Notably, any additional repeat dosing will be timed from date of this additional dosage of Evusheld. People who have not been given any doses of Evusheld must talk to their medical care provider to ascertain if, based on their individual circumstances, they have the eligibility to get it. Eligible people must be administered 300 mg of cilgavimab and 300 mg of tixagevimab dose.

Medical care personnel must contact people who received the previously authorized Evusheld dosage to return for an extra 150 mg cilgavimab and 150 mg tixagevimab dose as early as possible. Instead of 1.5 mL, the volume of each injection for the novel higher dose will be 3 mL. Thus, the injections must be restricted to large muscles on body that can accommodate this volume (like gluteal muscles).