Here's How Monoclonal Antibody Treatments Fight COVID-19, Plus How to Know If You're Eligible


Monoclonal antibodies have been a buzzy COVID-19 treatment for months, but it's not available for everyone. Currently, only select people qualify to receive a monoclonal antibody treatment if they've tested positive for COVID-19 or have been exposed to the virus. 

But what exactly is this treatment? Here's a breakdown of what monoclonal antibodies can—and can't—do to fight an active infection, as well as whether or not you're eligible. Plus, experts weigh in on why you still need the vaccine even if you've received this treatment.

Monoclonal-Antibodies-COVID-19-GettyImages-1289345741 Monoclonal-Antibodies-COVID-19-GettyImages-1289345741 (FDA). This means they can block SARS-CoV-2 (the virus that causes COVID-19) from attaching to your cells, and make it harder for the virus to reproduce and make you sick, according to the FDA. This means they may lessen symptoms, or even neutralize the virus.

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This particular treatment is actually not new to COVID-19. In fact, monoclonal antibodies are also used to treat some forms of cancer, William Schaffner, MD, an infectious disease specialist and professor at the Vanderbilt University School of Medicine, tells Health.

Who qualifies for monoclonal antibody treatment?

Currently, the Centers for Disease Control and Prevention (CDC) says that health care providers may recommend the treatment for those with COVID-19 who are at high risk of developing severe complications. Further, the National Institutes of Health (NIH) states that the COVID-19 Treatment Panel's current guidelines recommend using the treatment for those who are experiencing mild to moderate cases of COVID-19, as well as "for post-exposure prophylaxis (PEP) of SARS-CoV-2 infection in individuals who are at high risk for progression to severe COVID-19."

The NIH says that those who have underlying conditions or other certain factors that can increase the risk of developing severe COVID-19 qualify. The following are listed on the NIH website as conditions or factors that may make a person eligible to receive monoclonal antibody treatment:

The NIH says there was limited representation for the following factors and conditions in clinical trials, but they are still considered risk factors for progression to severe COVID-19 and people who have them may benefit from monoclonal antibodies:

How does monoclonal antibody treatment work?

The process of finding and getting monoclonal antibody treatment can be a little complicated, depending on where you live and your access to medical centers that provide the treatment. "Shortly after you are diagnosed with COVID-19, you can then contact a monoclonal antibody treatment center to see if you qualify," Dr. Schaffner says. (Many hospital centers are now offering this service, he points out, although your doctor should also be able to guide you.)

Almost all monoclonal antibodies are given through an intravenous (IV) infusion, though REGEN-COV (a combination of casirivimab and imdevimab, two different monoclonal antibodies) can also be administered through an injection. The FDA says that an IV infusion is strongly recommended, but subcutaneous injection is an alternate route of administration if, for some reason, there's no way to do it intravenously. "There is way more evidence for its use [via IV]," Dr. Adalja explains.

"The whole notion is that monoclonal antibody treatment will help prevent your development of subsequent severe disease," Dr. Schaffner says. However, it's important to note that there's a limited window of time when monoclonal antibody treatment will be effective at preventing severe COVID-19. "You need to get in early after your diagnosis," he explains. The Centers for Disease Control and Prevention specifically says that the treatment "should be administered as soon as possible after diagnosis" and within the first 10 days you experience symptoms.

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"In general, you have a very short window of time to find a place suitable to get to monoclonal antibody treatment and there's often bureaucratic red tape," infectious disease expert Amesh A. Adalja, MD, a senior scholar at the Johns Hopkins Center for Health Security, tells Health. "This is why they have been highly underutilized."

What monoclonal antibody treatments are currently available?

The FDA has issued an emergency use authorization (EUA) for REGEN-COV as well as the monoclonal antibody sotrovimab for the treatment of "mild to moderate" COVID-19 people aged 12 and over who are at a high risk of progressing to severe COVID-19. The FDA has also authorized the monoclonal antibody treatment Actemra (tocilizumab) to treat COVID-19 in hospitalized adults and those aged two and up who are receiving systemic corticosteroids and require supplemental oxygen, non-invasive or invasive mechanical ventilation, or extracorporeal membrane oxygenation (ECMO).

The FDA previously authorized a combination of two monoclonal antibodies, bamlanivimab and etesevimab, but later paused it after finding the treatment wasn't effective against certain COVID-19 variants. 

OK, so do you still need to get vaccinated if you receive monoclonal antibodies?

Doctors stress that it's still vital to get vaccinated against COVID-19. "It's always better to prevent an infection than to treat it," Dr. Schaffner says. "Relying on treatment—which isn't 100% guaranteed to work—is a bit hazardous."

There's also no guarantee that you'll be able to access monoclonal antibody treatment when you need it or that you'll even get a COVID-19 diagnosis in time, he says.

"I like to remind people that wise old Benjamin Franklin once said that an ounce of prevention—the vaccine—is much better than a pound of cure—monoclonal antibody treatment," Dr. Shaffner says. "You don't want to get COVID if you can help it."

The information in this story is accurate as of press time. However, as the situation surrounding COVID-19 continues to evolve, it's possible that some data have changed since publication. While Health is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations for their own communities by using the CDCWHO, and their local public health department as resources.

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