T-cells from common colds may give protection against COVID-19

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According to a recent UK study headed by Indian-origin researchers on Monday, people with greater numbers of T-cells from the common cold are less likely to get infected with SARS-CoV-2, the strain that causes Covid-19.

While there is evidence of diminishing antibody levels six months after vaccination, T-cells are also thought to play a key role in giving protection. The study, headed by Imperial College London researchers and published in the journal Nature Communications, claims to be the first to show that T cells play a protective function.

It started in September 2020 and looked at the amount of cross-reactive T-cells produced by prior common colds in 52 home contacts of positive COVID-19 individuals immediately after exposure to determine whether they developed an illness. It was discovered that the 26 persons who did not become infected had much larger amounts of those T-cells than those who did. Imperial did not specify how long the T-cells would be protected.

According to the researchers, the results give a blueprint for a second-generation universal vaccination that might protect against infection from existing and future SARS-CoV-2 variations, including Omicron.

According to the authors of the research published in Nature Communications, the internal proteins of the SARS-CoV-2 virus, which are targeted by T-cells, might provide an alternative target for vaccine producers.

“Our findings represent the most conclusive evidence yet that T cells generated by common cold coronaviruses protect against SARS-CoV-2 infection”, according to senior author Professor Ajit Lalvan. He is the Director of the National Institute for Health Research (NIHR) Respiratory Infections Health Protection Research Unit at Imperial College London. “These T cells protect by attacking proteins within the virus rather than the spike protein on its surface,” he added.


“The intracellular proteins targeted by the protective T-cells we found, on the other hand, change significantly less,” said Professor Ajit Lalvani, one of the study’s co-authors.

“As a result, they are extremely conserved throughout SARS-CoV-2 subtypes, including Omicron. New vaccines containing these conserved internal proteins might elicit wide protective T cell responses, protecting against both present and future SARS-CoV-2 variations.”

To fight against infection, these T cells targeted internal proteins inside the SARS-CoV-2 virus rather than the spike protein on the virus’s surface. Current vaccinations do not induce immune responses to these internal proteins.

The researchers claim that these internal proteins, in addition to current successful spike protein-targeting vaccines, give a novel vaccine target that might provide long-term protection since T cell responses remain longer than antibody responses, which fade after a few months.

The researchers acknowledge that the study had certain limitations, including the inability to predict demographic characteristics due to the study’s small size and that 88 percent of participants were of a white European race.

The Medical Research Council and the NIHR Health Protection Research Unit in Respiratory Infections in the United Kingdom supported the research.