by A newly developed blood test that measures a specific immune response in the body could help doctors gauge how much protection a person has against Covid-19, according to a new study.
The test, which targets the part of the immune system that confers long-term protection by making the body “remember” the virus, could help make sense of the complex web of immunity to Covid that now exists from person to person.
The test can, for example, measure immunity regardless of whether someone has developed a level of protection from one or more natural infections or from vaccinations and boosters. Others, who may have much lower levels of protection because they are immunocompromised, could also use the test to assess their vulnerability and see how they responded to vaccines, said Ernesto Guccione, an associate professor of oncological sciences and pharmacological sciences at Tisch Cancer. Institute at Mount Sinai.
“Ideally, it will give you a complete picture of your position and a complete picture of your immune protection,” said Guccione, one of the authors of the study published Monday in the journal Nature Biotechnology.
The researchers said they are now focusing on clinical trials to gain approval from both the Food and Drug Administration and the European Medicines Agency.
The test involves taking a small blood sample at a clinic and mixing it with protein fragments from the virus. The researchers then look to see if so-called T cells are activated in the sample.
T cells are the cornerstone of the immune system’s long-term memory and typically lie in wait until they detect the presence of foreign invaders. Unlike antibody levels, which can drop after vaccinations or infections, T cells can remember a virus years and sometimes decades later.
Whether through vaccinations or infections, T cells are primed to “pick up” bits of a virus, including variants that can evade protective antibodies. This means that the T cells will not prevent an infection from occurring, but they can prevent a patient from becoming seriously ill with Covid.
Previous studies have found that T cells can recognize all known variants of concern, including omicron, but Guccione said that’s an active area of research. Scientists continue to refine the test and are studying how well T cells respond against different variants.
“The data coming out so far is very encouraging,” he said. “The good news is that we develop immunity against multiple virus proteins, and many of them don’t tend to be mutated by variants.”
Testing for T cells has been largely limited to research laboratories, and the process is often expensive and difficult to perform on a large scale, Guccione said. However, the new kit is designed to be widely used, and results can usually be delivered in less than 24 hours, he added.
More research is needed, but he said the accuracy of the results is comparable to similar tests done in research labs.
Currently, the test can detect T-cell activation, but the researchers hope that later versions can provide more granular details, said Jordi Ochando, an assistant professor of cancer sciences at the Icahn School of Medicine at Mount Sinai and one of the co-authors. of the studio.
“To look at the intensity of T-cell immunity and correlate it with protection, we’re not at that level yet,” he said. “But we hope to be at some point.”
Future iterations may, for example, provide details on the magnitude and duration of a person’s immunity to Covid.
Each test run costs about $50, but Ochando said it’s possible that companies that license the product may include a markup in the price.
The test was developed by researchers at Mount Sinai and the Duke-NUS School of Medicine in Singapore. It is commercially available in Europe, as part of a license agreement with Hyris, a UK-based biotech company.
