Higher levels of T cells caused by the common cold make it less likely that a person will catch Covid, according to an “important discovery” outlined in a new peer-reviewed study.
The study, released on Monday by researchers at Imperial College London, is the “first evidence of a protective role for these T cells,” finding that their presence in high levels after a common cold can help to protect against Covid infection.
“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,” Professor Ajit Lalvani, senior author of the study, wrote. He said the cells “provide protection by attacking proteins within the virus, rather than the spike protein on its surface.”
The study began in September 2020, at a time when most UK citizens had not been infected with Covid, taking blood samples from participants within six days of them being exposed to the virus. It explored the levels of T cells created by the common cold that cross-recognized the Covid proteins.
In individuals who did not become infected with Covid, the levels of cross-reactive T cells were substantially higher than in those who caught the virus, showing that T cells target the internal proteins in Covid.
The researchers hope the study can influence the potential development of new Covid vaccines, as current jabs do not induce an immune response to internal proteins.
“New vaccines that include these conserved, internal proteins would therefore induce broadly protective T cell responses that should protect against current and future SARS-CoV-2 variants,” Professor Lalvani said.
Despite the “important discovery,” Dr Rhia Kundu, lead author of the study, was clear that existing T cells are “only one form of protection” and “no one should rely on this alone,” stating that vaccination is the most effective way to protect against Covid.