Anti-COVID Antibody Combo Receives Mixed Response

Monica J. Smith

December 23, 2021

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Dayna Stephens, 43, knew early on that the vaccinations against COVID-19 might not protect him as much as they would the general population. A kidney transplant recipient, he takes immune suppressing drugs that may compromise his body's ability to generate an adequate immune response to the vaccines.

So, when in early December the US Food and Drug Administration (FDA) granted emergency use authorization to AstraZeneca for its combination of the long-acting monoclonal antibodies tixagevimab/cilgavimab (Evusheld) to prevent COVID-19 in people with moderately to severely compromised immune systems, he was eager to try the agent.

"I wouldn't have any hesitancy in trying it; my primary care doctor and oncologist and transplant team would probably be on board," Stephens said. "I think it would give another level of protection than I have now, and I think I would feel a bit safer out in public and hanging out with friends, especially at this time of year."

Stephens is fully vaccinated and boosted, and he generally follows recommended safety protocols. But as a saxophone player, he can't mask up while performing, often indoors. The students he teaches at the Manhattan School of Music, in New York City, and William Paterson University, in Wayne, New Jersey, also follow safety protocols, but a certain degree of proximity is unavoidable.

"I've felt particularly guarded teaching, especially since I had five students test positive for COVID-19 during the fall semester," Stephens said.

But other patients and clinicians who spoke with Medscape Medical News were less enthusiastic, at least for the moment, to try the new agent.


Jennifer Heidmann, MD, medical director of Redwood Coast PACE (Program of All-Inclusive Care for the Elderly), Eureka, California, said she would welcome the antibody regimen as an additional layer of protection for her patients, but she has some reservations.

"As someone who takes care of people who are less wealthy, I have concerns about how available this will be to the whole population — all neighborhoods, all communities, all nations — because we know that in order to protect the vulnerable, everyone has to be involved," Heidmann told Medscape Medical News.

Heidmann said she also is concerned how the vaccine-hesitant might interpret the availability of the medication: "I wouldn't want this to be another reason people say, 'See, I don't need to get vaccinated because those at risk have this medication now.' This is another tool, but it can't stand alone. We still need everybody to get vaccinated."

Mary Wilson, 58, also a kidney transplant recipient, shares that wait-and-see attitude. Wilson, a psychotherapist in Brooklyn, New York City (who asked not to use her real name because of her profession), has lived with a heightened sense of vulnerability since her transplant team warned her about the possible threat of a novel virus about a month before most Americans were aware of it. After being vaccinated, she relaxed her vigilance a bit, but never felt free due to her immunocompromised status.

"I knew I always had to take extra precautions. I don't use public transportation at all. I wouldn't do crowds whether I was immunocompromised or not," she said. "I always have in the back of my mind, is this safe? Is this too risky?"

Wilson strolls her neighborhood in mask and gloves, fully vaccinated and recently boosted, and takes every precaution she can. But the new antibody agent does not interest her at this point.

"I would need to see the results in other trials. Science changes every day, so quickly," she said. "I would take my chances and wait it out."

The FDA's decision was based on a trial in which the 3441 patients randomized to receive treatment, administered via two intramuscular injections, had a 77% lower risk of developing COVID-19 than the 1731 controls. Additional analysis found the protective effect lasted 6 months.

Still, Andrew Karaba, MD, PhD, assistant professor in the Division of Infectious Diseases at Johns Hopkins University School of Medicine, Baltimore, said he is not ready to prescribe the antibodies to his patients.

"The vast majority of my patients are both vaccinated and immunocompromised," Karaba said. "Would this agent benefit them? It's hard to say. I think it's okay to extrapolate the data from that trial to the immunocompromised with caution, but this is part of the reason we're still evaluating which patients to prioritize."

Ruud Dobber, executive vice president and president of AstraZeneca's BioPharmaceuticals Business Unit, said the company has agreed to supply 700,000 doses of the product to the federal government, which will distribute them at no cost to patients. This amount would cover only 10% of the seven million immunocompromised people in the United States who would be eligible to receive the agent.

Also, the study on which the FDA based its decision was conducted in unvaccinated individuals at risk for severe COVID-19 due to their age and comorbidities. Most of them were immunocompetent.

The emergence of the Omicron variant makes things even murkier. Data from mid-December suggest, although not definitively, that the antibody combination is not as effective against Omicron as it is against Delta or the vaccine strain. "So that does give me pause against a blanket recommendation for it," Karaba said.

Until data emerge clarifying the role of the antibodies in preventing COVID-19 in immunocompromised patients, Karaba will continue to recommend his patients receive standard mRNA vaccines, encourage their close contacts to get vaccinated, and continue to follow the recommended safety protocols.

"Really, being vaccinated and having their close contacts vaccinated is by far and away the best thing patients with solid organ transplants and other immunocompromised conditions can do to protect themselves," he said.

Karaba has received consulting fees from Roche. Heidmann reported no relevant financial conflicts of interest.

Monica J. Smith is a medical writer in New York City.

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