New AstraZeneca COVID Prevention Drug Will Not Replace Vaccines

AstraZeneca’s Evusheld is not the first monoclonal antibody treatment to earn authorization by the Food and Drug Administration (FDA) for use against COVID-19, but it is the first medication to be authorized specifically to prevent certain people from developing COVID in the first place.

The FDA said in December that Evusheld could reduce a person’s chance of developing COVID-19 by 77%. The early data also suggested that the treatment could be protective against the Omicron variant.

However, experts want people to understand that a preventative treatment like Evusheld is not a substitute for vaccination in people who can safely receive one.

What Is Evusheld?

Evusheld is a combination of two monoclonal antibodies—tixagevimab and cilgavimab—that are designed to target the spike protein of the SARS-CoV-2 virus. This, in turn, blocks the virus from getting inside human cells. The drug is given as two injections, one right after the other.

Stuart Ray, MD, a professor of medicine at Johns Hopkins Medicine, told Verywell that the protection from a treatment like Evusheld is a type of “passive immunization” that is less durable than the protection that you get from vaccines.

Who Is Evusheld For?

The FDA’s authorization specifies that Evusheld is only for people who are not currently infected with COVID and who have not had recent close contact with someone who is infected.

In addition, Evusheld recipients must either:

• Have a moderately to severely compromised immune system because of a medical condition or because they are taking immunosuppressant medications (such as anti-organ rejection drugs after a transplant, as well as some types of chemotherapy) OR
• Have a history of a severe adverse reaction to a COVID-19 vaccine or components of a COVID-19 vaccine

How Does Evusheld Compare to Vaccination?

COVID vaccinations are safe and effective. Experts want to make sure that people understand that Evusheld, and other treatments like it, are not intended to replace a vaccine for most people.

“If you’re still not vaccinated against COVID-19, your best protection is to get the full vaccine dose and booster,” William Schaffner, MD, professor of medicine at the Vanderbilt University School of Medicine, told Verywell.

Schaffner said that while Evusheld does supply antibodies to help protect against COVID, it must be given again every 6 months. On the other hand, the protection you get from the COVID vaccines may last longer.

Your body’s antibody response to protect you against COVID is crucial. Schaffner said the current vaccines also provide other important immune responses, including T cell and B cell activation, but Evusheld does not.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.