Tixagevimab/cilgavimab, sold under the brand name Evusheld, is a combination of two human monoclonal antibodies, tixagevimab (AZD8895) and cilgavimab (AZD1061) targeted against the surface spike protein of SARS-CoV-2[15][16] used to prevent COVID-19.

[20] In 2020, researchers at Vanderbilt University Medical Center discovered particularly potent monoclonal antibodies, isolated from COVID-19 patients infected with a SARS-CoV-2 circulating at that time.

[22][23] The trial reported that those receiving the cocktail showed a 77% reduction in symptomatic COVID-19 and that there were no severe cases or deaths.

[12] Also in October 2021, AstraZeneca requested emergency use authorization for tixagevimab/cilgavimab to prevent COVID-19 from the US Food and Drug Administration (FDA).

[12][36] In January 2023, the FDA revised the EUA for Evusheld to limit its use to when the combined frequency of non-susceptible SARS-CoV-2 variants nationally is less than or equal to 90%.