First of Its Kind Blood Test Measures Immune Response to COVID Vaccine

By LabMedica International staff writers
Posted on 12 Aug 2022

Image: The test measures both antibody and T-cell response to COVID-19 vaccination among immunocompromised patients (Photo courtesy of Pexels)

Multiple sclerosis (MS) is caused by the immune system attacking the protective sheath (myelin) that covers nerve fibers, resulting in symptoms such as muscle pain, spasms, and even paralysis. MS patients have to be administered immune-suppressing anti-CD20 (aCD20) treatment every six months that eliminate B-cells, which helps to manage symptoms, but leaves their immune systems weakened. Typical measures of immune response to the COVID-19 vaccine can be misleading in this group of patients. Now, a first of its kind test will provide MS patients who have undergone immune-suppressing treatment with a clear picture of how exactly their bodies’ immune systems responded to the COVID-19 vaccine.

The first-in-class test developed by researchers at the Perelman School of Medicine at the University of Pennsylvania (Philadelphia, PA, USA) is aimed at examining both antibody and T-cell response to COVID-19 vaccination in patients with MS who have undergone aCD20 treatment. Many patients with MS undergo aCD20 treatment – which depletes the B-cells that contribute to the MS attacks. Because B-cells are responsible for antibody production, patients’ ability to produce antibodies that prevent viruses from entering and infecting a person’s cells is significantly muted when the B-cells are depleted with a CD20 treatment.

The immune response to vaccination is usually evaluated by measuring the amount of antibodies in the blood. While this method can be informative for patients with a healthy immune system, patients who received aCD20 infusions would appear unable to mount an immune response to vaccination when, in reality, research shows that they are actually able to mount a robust T-cell response. The new test measures both antibody and T-cell response to COVID-19 vaccination among MS patients, then integrates results into the electronic health record to aid in clinician and patient decision-making

“MS patients who receive aCD20 infusions often ask their doctor if it’s safe for them to go to something like their grandson’s graduation, or their granddaughter’s wedding,” said Amit Bar-Or, MD, FRCPC, director of the Center for Neuroinflammation and Experimental Therapeutics and chief of the division of MS and Related Disorders, who helped develop the test. “With this new test, our hope is that clinicians will be able to measure the strength of a patient’s complete immune response to the COVID vaccine, and use results to guide decision-making about different activities in their lives.”

“If a patient mounted a T-cell response to their first vaccine doses, their provider might advise them to schedule a booster prior to an event like a graduation or wedding,” Bar-Or added. “But if they didn’t show a response to previous doses, the provider may explore other prophylactic therapeutics and could advise on other precautions, like wearing an N95 mask and eating outdoors.”

“Right now, the most pressing application of this test is for COVID-19, but the immune system plays such a huge role in how the body fights most illnesses, there’s enormous potential for this test down the line,” said E. John Wherry, PhD, chair of Systems Pharmacology & Translational Therapeutics, who also led the test’s development. “What’s more, many treatments for a range of conditions, like cancer, can weaken a patient’s immune system. We’re hopeful that, in the future, this test could be used widely to measure the ability of patients’ immune systems to fight a variety of illnesses.”

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