University of Pennsylvania Develops Blood Test for COVID-19 Vaccine Response

Researchers at the Perelman School of Medicine at the University of Pennsylvania developed a new test which will allow multiple sclerosis patients who have undergone immune-suppressing treatment to get a clear picture of how their bodies’ immune systems would respond to the COVID-19 vaccine. The new test measures both antibody and T-cell response to COVID-19 vaccination among multiple sclerosis patients, then integrates results into the electronic health record to aid in clinician and patient decision-making.

The New Test, a First of Its Kind in Today’s Healthcare System

Typical measures of immune response can be misleading in this group of patients, but this first of its kind test provides a clear picture that can be integrated into the electronic health record, which clinicians can access to counsel patients. 

Developed with support from the National Institutes of Health Autoimmunity Center of Excellence at Penn Medicine, the first-in-class test is aimed at examining both antibody and T-cell response to COVID-19 vaccination in patients with multiple sclerosis (MS) who have undergone immune-suppressing anti-CD20 (aCD20) treatment. 

Caused by the immune system attacking the protective sheath (myelin) that covers nerve fibers, MS can result in symptoms such as muscle pain, spasms, and even paralysis. Typically administered every six months, aCD20 infusions eliminate B-cells, which helps to manage symptoms, but leaves patients’ immune systems weakened.

“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.”

How Does the Immune System React to Vaccination

The immune system has two parts. The first part, which uses B-cells to produce antibodies, acts like a sieve keeping the tea leaves from entering your cup: antibodies filter out viruses and prevent them from entering the body and infecting a person’s healthy cells. However, antibodies can’t always catch every viral particle, and some get through to cause infection – similar to how tiny specs of tea leaves can go through the sieve and end up in your tea. The second part of the immune system are T-cells, which hunt down virally infected cells and eliminate them so that the virus can’t spread. They’re the shakes you give a sieve to help the liquid go through. 

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 normally evaluated by how many antibodies one has in the blood. This method is fine for patients with a healthy immune system, but those who received aCD20 infusions would appear unable to have an immune response to vaccination when, in reality, research shows that they can really have a robust T-cell response.

“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 said. “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.”

Efforts to Prevent and Treat COVID-19, Beneficial in Battling Other Illnesses

We are only starting to consider the long-term benefits of the billions of dollars that went into the research and development of vaccines to treat COVID-19. Medical experts claim that it is all expected to pay off in medical scientific dividends for several decades. The work completed to battle COVID-19 is expected to play a huge role in how doctors treat cancer, influenza, cystic fibrosis, and many other conditions and diseases. The way the body reacts to various new vaccines and treatments offers insight for reactions and possible treatments for other ailments. When it comes to the COVID-19 vaccines, these have been developed quite rapidly, and the need to evaluate how different subjects respond to the vaccines increased while the pandemic kept on going. More importantly, the virus itself constantly evolving, it was even more important to try and adapt the vaccines to the new variants, while keeping patients with concordant diseases  safe. 

Pfizer Inc. and BioNTech, for instance, announced June 25th positive data evaluating the safety, tolerability, and immunogenicity of two Omicron-adapted COVID-19 vaccine candidates: one monovalent and the other bivalent, a combination of the Pfizer-BioNTech COVID-19 Vaccine and a vaccine candidate targeting the spike protein of the Omicron BA.1 variant of concern. 

When it comes to the new blood test for immune-challenged patients, this also might be used for different other treatments.

 “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.”