The U.S. Food and Drug Administration (FDA) on Dec. 8 issued an emergency use authorization for an AstraZeneca COVID-19 antibody drug designed to help prevent infection in people with compromised immune systems. The drug, called Evusheld, is a combination of two long-acting synthetic antibodies: tixagevimab and cilgavimab, which are derived from B-cells donated by patients who have recovered from the SARS-CoV-2 virus. It is the first antibody therapy authorized in the United States for preventative COVID-19 treatment. Both of the antibodies work by mimicking the immune system’s ability to fight the virus and are specifically designed to act against the spike protein of SARS-CoV-2, blocking the virus’ attachment and entry into human cells. Evusheld, formerly known as AZD7442, is only authorized for use in individuals who are not currently infected with SARS-CoV-2 and who have not recently been exposed to an individual infected with the virus. “Based on the FDA’s review of the totality of the scientific evidence available, the agency has …