FDA authorizes AstraZeneca antibody cocktail for immunocompromised people

The Food and Drug Administration (FDA) on Wednesday authorized AstraZeneca’s antibody cocktail designed to prevent COVID-19 in immunocompromised people who may not mount an adequate immune response to vaccines.

The FDA granted AstraZeneca’s Evusheld, previously known as AZD7442, an emergency use authorization to be given to certain adult and pediatric patients who are not currently infected with COVID-19 and have not been exposed to someone with the virus.

In order to take the medicine, the patients need to either have moderate to severely compromised immune systems due to medical conditions or immunosuppressive medications or treatments or to have a history of a severe adverse reaction to the vaccine or its ingredients. 


The FDA noted Evusheld should not function as “a substitute for vaccination in individuals for whom COVID-19 vaccination is recommended.”

“Vaccines have proven to be the best defense available against COVID-19,” said Patrizia Cavazzoni, the director of the FDA’s Center for Drug Evaluation and Research. 

“However, there are certain immune compromised individuals who may not mount an adequate immune response to COVID-19 vaccination, or those who have a history of severe adverse reactions to a COVID-19 vaccine and therefore cannot receive one and need an alternative prevention option.”

The preventative cocktail, composed of the long-acting monoclonal antibodies tixagevimab and cilgavimab, is instructed to be given in two separate consecutive intramuscular injections. That dose could prevent COVID-19 in at-risk individuals for six months. 

AstraZeneca submitted its request for emergency use authorization in October based on data showing the cocktail was 77 percent effective at preventing symptomatic COVID-19. A company analysis from last month found the drug combination to be more than 80 percent effective.

The drug was tested in a trial involving participants older than 59 at higher risk for COVID-19 who had not gotten vaccinated or had a previously confirmed infection.


With about 7 million Americans considered to be immunocompromised, the antibody cocktail could help them develop a stronger immune response to prevent COVID-19 infection. AstraZeneca noted that studies are currently ongoing to see how the omicron variant affects Evusheld.

The pharmaceutical company said it has struck a deal to provide the U.S. with 700,000 doses of Evusheld.

The possible side effects of Evusheld include hypersensitivity reactions, bleeding at the injection site, headache, fatigue and cough. 

The FDA also noted that more trial participants who took the Evusheld had serious cardiac adverse reactions than the placebo, although the incidents were “infrequent” and all these participants had risk factors or a history of cardiac disease. The agency said, “it is not clear if Evusheld caused these cardiac adverse events.”