If antibodies fail, T cells in Covid-recovered people could shield from Omicron: US study

According to a new study by researchers in the United States, the body’s immune system, which is driven by T cells, may be able to oppose the new SARS-CoV-2 variant Omicron in Covid-recovered persons, even if it is able to avoid antibodies.

A T cell is a type of white blood cell that plays a key role in the immune response, including destroying infected cells and releasing proteins that function as signals for other cells to produce antibodies.

The study has been conducted by the US National Institute of Allergy and Infectious Diseases and Johns Hopkins University. It was posted on the preprint portal bioRxiv on 9 December and is yet to be peer-reviewed.

With a large number of reinfections (people who have had Covid before being infected with Omicron) being reported, as well as over 30 mutations in the Omicron’s spike protein (the protruding part of the coronavirus that allows the pathogen to enter the host cell), which most vaccines target, there is a concern that the variant may be capable of escaping the immune response generated by both prior infection or vaccination.

Now, data from the study suggests that virtually all individuals with existing anti-SARS-CoV-2 CD8+ T cell responses should recognise the Omicron variant. CD8+ T cells are those that are known to initiate the death of infected cells.