In-Depth: What are monoclonal antibodies and how do they work?

Monoclonal antibodies
Posted at 12:02 PM, Aug 20, 2021
and last updated 2021-08-20 17:44:56-04

TAMPA, Fla. — Governor Ron DeSantis has crisscrossed the state touting the effectiveness of monoclonal antibody treatment for COVID-19 while setting up large sites to deliver doses to Floridians battling the deadly disease. But many may not know what monoclonal antibodies are and how the treatment works.

RELATED: Gov. DeSantis announces new monoclonal antibody sites in Tampa Bay

What are monoclonal antibodies?
The human body naturally makes antibodies to fight infections. But, when a novel virus appears, the body may not have the antibodies needed to recognize the new disease. In this case, SARS-CoV-2, or COVID-19’s appearance sparked such a problem for people around the world. That’s where monoclonal antibodies come into play.

According to the U.S. Department of Health and Human Services, monoclonal antibodies, or mAbs, are made in laboratories to fight a particular infection. In the current case, the mAbs fight COVID-19 and are given through infusions. The mAb treatments can then help the body fight the virus, and in some cases help people avoid hospitalization for COVID-19.

Here's how Dr. Kami Kim, director of infectious diseases at the University of South Florida and an attending physician at Tampa General Hospital described it:
"There are proteins in the body called antibodies and they fight off infections. So the biotechnology industry figured out how to use those to basically make targeted missiles toward molecules that were causing problems,” Dr. Kim said. “These antibodies are called neutralizing antibodies because they neutralize the virus. And so if you give these antibodies early on you can prevent the virus from getting into your cells.”

Going a little deeper, the National Institute of Health said the mAb treatment target “the spike protein” that helps COVID-19 enter cells. The NIH said at the beginning of August, three mAb treatments have emergency use authorization approval from the Food and Drug Administration: Bamlanivimab plus etesevimab, Casirivimab plus imdevimab, and Sotrovimab.

The Health and Human Services Department said the mAb treatment differs from the vaccine because the vaccine triggers the body’s immune system but can take up to two weeks to develop enough antibodies to prevent some kinds of infection. However, if you already have the virus in your system, the mAb treatment gives your body the antibodies it needs to help protect itself.

How effective are the treatments?
Studies on the mAb treatment have shown them to be effective at preventing high-risk patients from developing severe COVID-19 symptoms that might require hospitalization.

Regeneron, one of the makers of a mAb treatment, said treatment within 10 days had a 70% reduced risk of hospitalization or death. GlaxoSmithKline’s mAb treatment showed an 85% reduction in the risk of hospitalization or death.

How much do mAb treatments for COVID-19 cost?
The treatments are free across Florida. To date, the U.S. has spent more than $2 billion on treatment doses to keep them free.

Who qualifies for monoclonal antibody treatment?
The Department of Health and Human Services lays out just a few requirements to receive monoclonal antibody treatment. Those requirements include:

  • Be 12 years of age or older
  • Test positive for COVID-19 in the last 10 days
  • Receive a referral from their healthcare provider for the treatment
  • Find a treatment center and get the infusion

While those are the federal guidelines, Governor DeSantis has worked with state health officials to remove the second qualification meaning a prescription/referral is not need in the state of Florida to receive the treatment.

When should I seek treatment?
Dr. Kim said timing is everything with the monoclonal antibody treatment.

“We’re recommending that people get tested early on and particularly if they’re in a high-risk category that they contact their doctor and figure if they can get monoclonal antibody. Within a week, if you’re immunocompromised, we give you a few more days, but it’s pretty clear from all the studies in our own data that day 3 is better than day 7. And some people make the mistake of, let me see if I feel bad and then see if I need to go see a doctor and that’s actually the wrong thing to do, particularly if you’re in a high risk category.”

What can I expect during the treatment?
The treatment is delivered to the body through an intravenous (IV) infusion and depending on the type of mAb treatment you receive, the process can take between two to three hours. According to the HHS, the treatment typically is carried out thusly:

  1. Medical staff conduct a screening
  2. The staff begins the IV treatment to deliver the mAbs directly into your body in roughly one hour
  3. You will have to stay at the infusion center for another hour to ensure you don’t have an allergic reaction or other side effects to the mAb treatment. HHS said, “these reactions are rare, but the staff must observe you for this hour.”
  4. You are released to go home

Are there side effects?
According to the Food and Drug Administration, allergic reactions to mAb treatment are rare but have happened. The National Institutes of Health reported that adverse effects from mAb treatments included: hypersensitivity, including anaphylaxis & infusion-related reactions, along with rash, diarrhea, nausea, dizziness, and pruritis (itchy skin) have been reported. This is why patients receiving the treatments are monitored for an hour after the treatment is completed.

Am I cured once the treatment has been given?
According to HHS, even if you start to feel better, you are still in a time period where you can spread the virus. This is especially true of the delta variant, which can cause a much higher viral load. As a result, patients need to isolate until ALL the following things happen:

  • At least 10 days have passed since your first symptoms of COVID-19
  • You haven’t had a fever in at least 24 hours, without taking any medications that reduce fever
  • Your other symptoms of COVID-19 are improving

NOTE: HHS said patients who receive mAbs should follow all of their healthcare providers' instructions as each patient’s personal health history may require people to meet additional conditions to leave isolation.

Does this replace the need to get vaccinated?
Absolutely not!

“People are very confused about vaccines," Dr. Kim said. "They definitely work. Yes, people are getting COVID more frequently than with the than with the other variants, but those vaccinated people are getting something like severe cold or a mild flu, they are not coming into the hospital with bad pneumonia, needing a ventilator, things like that. So the vaccine is definitely working to prevent the more serious complications of COVID.”