How strong is your Covid immunity?  A blood test could give insight

A newly developed blood test that measures a specific immune response in the body could help doctors assess how well a person is protected against Covid-19, a new study has found.

The test, which focuses on the part of the immune system that confers long-term protection by tricking the body into ‘remembering’ the virus, could help make sense of the complex tangle of Covid immunity that now exists from one person to another.

The test can, for example, measure immunity, whether a person has developed a level of protection against one or more natural infections or against 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, associate professor of oncological sciences and of Pharmacological Sciences at the Tisch Cancer Institute of Mount Sinai.

“Ideally, this will give you the full picture of where you are and the full 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 then focusing on clinical trials to gain approval from the Food and Drug Administration and the European Medicines Agency.

The test involves taking a small sample of blood at a clinic and mixing it with protein extracts from the virus. The researchers then look to see if the so-called T cells are activated in the sample.

T cells are the building block of the immune system’s long-term memory and usually wait for them to detect the presence of foreign invaders. Unlike antibody levels, which can decline following vaccinations or infections, T cells can recall a virus years or even decades later.

Whether through vaccinations or infections, T cells are primed to “recall” fragments of a virus, including variants that can evade protective antibodies. This means that T cells will not prevent an infection from occurring, but they can prevent a patient from becoming seriously ill from Covid.

Previous studies have shown that T cells can recognize all known variants of concern, including omicron, but Guccione said this is an active area of ​​research. Scientists continue to refine the test and study how well T cells react against different variants.

“The data released so far is very encouraging,” he said. “The good news is that we develop immunity against several proteins in the virus, and many of them don’t tend to be mutated by the variants.”

Tests to detect T cells have been mostly limited to laboratories for research purposes, and the process is usually expensive and difficult to perform on a large scale, Guccione said. The new kit, however, is designed for wide use 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 performed in research labs.

Currently, the test can detect T-cell activation, but researchers hope later versions can provide more granular detail, said Jordi Ochando, assistant professor of oncology sciences at the Icahn School of Medicine at Mount Sinai and one of the co-authors of the study.

“To look at how strong T-cell immunity is 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 extent and duration of a person’s immunity to Covid.

Each test costs around $50 to run, but Ochando said companies licensing the product may include a markup on the price.

The test was developed by researchers at Mount Sinai and Duke-NUS Medical School in Singapore. It is marketed in Europe, under a licensing agreement with Hyris, a UK-based biotechnology company.

By cardgo

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