Monoclonal antibodies available and effective, but don’t replace vaccine, doctors say

Monoclonal antibodies are a treatment available to high-risk patients early on in their COVID-19 infection. We find out how they work and what they do.
Published: Sep. 1, 2021 at 4:48 PM AKDT
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ANCHORAGE, Alaska (KTUU) - Tucked away in the corner of a Northeast Anchorage shopping center, an electronic doorbell is mounted to the outside of a once-automatic door. Here, medical workers are finding themselves on the doorstep of the fight against COVID-19 in Alaska.

The state-run monoclonal antibody infusion center treats about 20 patients a day, according to director Jyll Green, a family nurse practitioner who oversees the site. Since it was stood up last Monday, Green said her phones have been ringing off the hook, with patients looking to get early treatment for their COVID-19 infection.

As the delta variant of COVID-19 spreads rapidly through Alaskans in what many had hoped would be a COVID-free summer, hospitalizations are on the rise, exceeding the previous record of COVID-19 patients in the state’s health care facilities — on top of what’s already a usually busy summer season full of recreational injuries, car crashes and elective procedures.

“We just don’t want the hospital system to get overwhelmed, and it is overwhelmed,” Green said Wednesday as she prepared the clinic for a new round of patients. “So if we can keep most of these patients that come here from progressing to the point that hospitalization is required, we are helping the hospital system.”

The monoclonal antibody treatment is authorized for people who are considered “high risk” under U.S. Center of Disease Control and Prevention guidelines for severe COVID-19 illness, who either test positive or are a close contact with a positive case.

Those high-risk conditions include:

  • Not being fully vaccinated
  • Being age 65 or older
  • Obesity or being overweight
  • Pregnancy
  • Chronic kidney disease
  • Diabetes
  • Having a weakened immune system from health conditions or medications
  • Heart disease
  • Chronic lung diseases like COPD or asthma
  • Sickle cell disease

Not being fully vaccinated in itself may not qualify a patient for monoclonal antibody treatment. Dr. Coleman Cutchins, a clinical pharmacist with the Alaska Department of Health and Social Services, said monoclonal antibodies must be prescribed by a health provider, which is why the department suggests reaching out to one’s own primary care provider first. Individual providers can access the treatment free from the federal government, as well. Those without a primary care doctor can call the state’s COVID-19 help line, and providers at the state infusion sites can determine eligibility as well.

“If you don’t meet that CDC criteria for being in high risk for developing sever COVID, we presume that your immune system is robust enough that you’ll be able to make your own antibodies and fight COVID-19, so you don’t develop the severe symptoms, so you’re not a candidate,” Green said.

What are monoclonal antibodies?

The monoclonal antibody treatment REGEN-COV, consisting of the drugs casirivimab and imdevimab, was given Emergency Use Authority for use for COVID-19 by the Food and Drug Administration in November 2020. The authorization was revised earlier this month, to add that it could be used as a preventative measure for high-risk individuals as well.

Cutchins described their effectiveness compared to vaccines and natural infection in an interview with Alaska’s News Source.

He described that antibodies provided by the vaccine are more effective than those from natural infection, due to their specific target of a specific, external receptor on the virus.

“If you have the natural antibodies, your immune system can act quick, but the monoclonal is essentially giving you a whole bunch of synthetic antibodies that have a target on one end for the SARS-CoV-2 virus, and the target on the other end for your immune system to attach to. So it stops the virus from really replicating in high numbers and overwhelming your body.”

While natural immunity can help fight the virus, Cutchins said the vaccines are more specifically targeted to the receptors on the outer structure of the virus, and even after a natural infection of COVID-19, each person’s immunity to re-infection varies.

“Immunity you get from vaccine is very consistent, and it’s very measured, and it’s really robust and really specific to that one part of the virus that you need to identify,” Cutchins said. After natural infection, he says, “you could develop really good immunity to a part of the virus that’s on the inside, and your body can’t (identify) it there. So it’s kind of like taking a picture of someone’s back ... verses a picture of their face.”

While this specific configuration of monoclonal antibodies is engineered toward SARS-CoV-2, the coronavirus strain behind COVID-19, it’s not the treatment’s first, or only application. Monoclonal antibodies, overall, are grown in a lab setting that can be targeted to anything. They are most commonly used today to target certain types of cancers and autoimmune diseases, and to treat newborns in the neonatal intensive care unit when there is a high prevalence of RSV, a respiratory virus that can be very dangerous to infants.

The FDA and Emergency Use Authorization

Monoclonal antibodies are not yet fully authorized by the Food and Drug Administration for use against COVID-19, but Cutchins says that doesn’t mean the drugs have not been well-tested. While drugs like Remdesivir and Comirnaty, the Pfizer-BioNtech brand name for its mRNA vaccine against COVID-19, have achieved full FDA approval in a relative short amount of time, part of that can be attributed to the urgency of the worldwide pandemic.

Cutchins, who has worked on drug studies previously in his career, said a lot of the drug approval process is bureaucracy. Cutchins said it can sometimes take years to get enough people enrolled in a study, and years for the FDA to give approval to go on to the next step, solely because of the other applications in line.

Emergency Use Authorization, he said, goes through all those steps, but without the wait.

“They get a fast pass to the front of line every time,” Cutchins said.

The difference in application of an Emergency Use Authorization and full approval, Cutchins said, is what doctors and companies are allowed to do with it. Drugs under the emergency authorization cannot be used off-label, for applications other than what they are approved for. Drug companies also are not allowed to advertise for drugs that are under that authorization, because they were approved in a state of emergency.

Will monoclonal antibodies end the pandemic?

While monoclonal antibodies are helpful in keeping COVID-19 positive patients out of the hospital, they are not the key to ending the pandemic, said Green, who administers the treatments in Anchorage.

“This is a safety net for people who so far have opted not to get vaccinated, or people who are vaccinated and at high risk for developing severe COVID,” she told Alaska’s News Source Wednesday.

She emphasized the importance of people getting vaccinated first.

Cutchins said the treatment is no replacement for a vaccine.

“If you’re standing on the edge of a cliff,” he posited. “you want a guardrail to prevent you from falling over that cliff in the first place, which is like what vaccine does for us. But if you do fall over that cliff, you would want something like a safety net 10 feet down to catch you, that would be better than falling all the way.”

Monoclonal antibodies do have their limits. Because they are a sterile fluid, they must be given by a health professional, either by IV or subcutaneous injection, and patients need to be observed afterward. And while they can help keep the burden off of hospitals, their limitation of effectiveness to a short window after initial infection also limits their usefulness as a tool to end the pandemic.

“If you’re too sick, if you are eligible for hospitalization, due to low oxygen saturation, we will send you to the hospital from here, and we’ve done that a few times,” Green said. “When your disease is so severe, this is not the right treatment for you.”

To find out more information on monoclonal antibody treatment, or to find out whether you qualify for the treatment, call the state’s COVID-19 help line at (907) 646-3322.

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