People with higher levels of T cells from common cold coronaviruses are less likely to become infected with Covid-19, offering a possible blueprint for a second-generation of vaccines against future variants, a UK research team made up of an Indian-origin scientist said on Monday.

The study, published in Nature Communications and led by Imperial College researchers, claims to provide the first evidence of a protective role for T cells.

While previous studies have shown that T cells induced by other coronaviruses can recognise SARS-CoV-2, the strain which causes Covid-19, the new study examines how the presence of these

T cells at the time of SARS-CoV-2 exposure influences infection. They believe their findings provide a blueprint for a second-generation, universal vaccine that could prevent infection from current and future SARS-CoV-2 variants, including omicron.

“Our study provides the clearest evidence to date that T cells induced by common cold coronaviruses play a protective role against SARS-CoV-2 infection. These T cells provide protection by attacking proteins within the virus, rather than the spike protein on its surface,” said senior author Prof. Ajit Lalvani, director of the National Institute for Health Research Respiratory Infections Health Protection Research Unit at the Imperial College, London.

“The spike protein is under intense immune pressure from vaccine-induced antibody, which drives evolution of vaccine escape mutants. In contrast, the internal proteins targeted by the protective

T cells we identified mutate much less. Consequently, they are highly conserved between the various SARS-CoV-2 variants, including omicron,” he explained.

“New vaccines that include these conserved, internal proteins would therefore induce broadly protective T cell responses that should protect against current and future variants,” he said.