What to Know About Monoclonal Antibodies for COVID-19

What Are Monoclonal Antibodies?

They are a type of medical treatment. Scientists make monoclonal antibodies, or mAbs, in a lab. They work like the natural antibodies your body makes to fight illness. They go out into your body to identify and attack germs like the coronavirus that causes COVID-19. Research seems to show that some mAbs, when used correctly, may help some people with COVID-19.

How Do Monoclonal Antibodies Work?

To make monoclonal antibodies, scientists expose a specific type of cell from the immune system to a particular viral protein -- in this case, SARS-CoV-2, the virus that causes COVID-19. They can then design the mAb to target a particular virus or a specific part of the infection process.

For COVID-19, scientists made several mAbs that bind to the spike protein on the virus's surface. This stops the virus from invading human cells.

The FDA had given emergency use authorization, or EUA, for some mAbs at different points during the COVID-19 pandemic. EUA means doctors can use them in certain cases even though they haven't been through the full FDA approval process.

But recommendations for COVID-19 mAb treatments are in constant flux. So check the CDC or other government websites for the latest recommendations.  

For example, in January 2022, the FDA said two mAb treatments that previously had EUA (bamlanivimab plus etesevimab, and casirivimab plus imdevimab) are unlikely to work against Omicron and should not be used in most cases. Other types of medications, like antivirals, may be more effective against the Omicron variant, the FDA said.  

In December 2021, the FDA approved the mAb Evusheld (tixagevimab and cilgavimab) to prevent COVID-19 infection (not for treatment after infection). It's only for people 12 and older who weigh at least 88 pounds and have a weakened immune system or a history of bad reactions to the COVID-19 vaccine.

Monoclonal antibodies, like most medications, carry risks and side effects that you and your doctor need to weigh against any possible benefits. They can cause allergic reactions or infection at the injection site, among other problems. These risks become less worth it when the drug is known not to work against your illness.


Who Gets mAbs for COVID-19?

The way doctors use mAbs to treat or prevent COVID-19 changes constantly as the virus continues to evolve and scientists learn more about how these medications work. There may be different recommendations for individual drugs or drug combinations.

To find out if these treatments are right for you, you can start by checking the online COVID-19 information sites at the CDC, FDA, or NIH. After that, talk to your doctor to find out if mAbs are good for your particular age, illness, and health history.

Except for the mAb Evusheld (tixagevimab and cilgavimab, doctors tend to use mAbs in people with COVID-19 who aren't sick enough for hospital care but have risk factors for serious infection. These might include people who:

  • Are older than 65
  • Are obese
  • Have a weak immune system
  • Have certain medical conditions

Talk to your doctor as soon as possible if you have COVID-19 symptoms and think you could be a candidate for mAbs because early treatment is key to their success.

WebMD Medical Reference Reviewed by Melinda Ratini, DO, MS on February 03, 2022



Centers for Medicare & Medicaid Services: “Monoclonal Antibody COVID-19 Infusion.”

European Medicines Agency: “EMA reviewing data on monoclonal antibody use for COVID-19.”

FDA: “Coronavirus (COVID-19) Update: FDA Authorizes New Long-Acting Monoclonal Antibodies for Pre-exposure Prevention of COVID-19 in Certain Individuals,” “Coronavirus (COVID-19) Update: FDA Limits Use of Certain Monoclonal Antibodies to Treat COVID-19 Due to the Omicron Variant,” “Coronavirus (COVID-19) Update: FDA Revokes Emergency Use Authorization for Monoclonal Antibody Bamlanivimab.”

Journal of the American Medical Association: “Monoclonal Antibodies for COVID-19.”

NIH COVID-19 Treatment Guidelines: “Anti-SARS-CoV-2 Monoclonal Antibodies.”

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