The immunity you get after catching a common cold may offer some form of protection against Covid-19, a new study has shown.
The study published by the journal Nature Communications by researchers from the Imperial College London, found that people with higher levels of T-cells (immune fighters) from the common cold could stand a better chance should they come in contact with the coronavirus.
Dr Ahmed Kalebi, a consultant pathologist who was not part of the study, explained to the Newszetu Tuesday that T-cells are known to directly attack infectious microorganisms such as viruses and bacteria and destroying them by directly coming into contact with the infectious microorganism and using chemical compounds to destroy them.
The researchers were trying to find out why some people who are exposed to the coronavirus do not get infected even when all the odds show that they put themselves at risk of catching the virus.
The study participants were grouped into two; those who had a positive test and those who had a negative test.
T-cells
In the participants who had a negative Covid-19 test, researchers found out that they had high numbers of the ‘memory’ T-cells from a common cold, which they linked with the negative test outcome.
Dr Kalebi explained that a common cold is caused by different viruses and the coronavirus family is one of them.
“The commonest viruses causing common cold are rhinovirus, coronavirus, Respiratory Syncytial Virus (RSV) and parainfluenza viruses, in that order,” he explained.
The researchers assessed people who had been found positive for Covid-19 and traced their earliest point of exposure to the coronavirus.
Cross-reaction
Dr Kalebi said that memory T-cells, which have previously attacked other viruses that cause the common cold are able to cross-react with SARS-COV-2.
“Cross-reaction means that whatever chemical such as cytokines that are produced by the immune cells targeting one type of virus to react with that targeted virus, and whatever T-cells they produce acting against that virus, end up reacting against other viruses which the immune cells have not targeted, so they are cross-reacting, the way cross-fire means soldiers targeting a specific enemy but their firepower ends up hitting others who are not targeted,” he explained.
“The study has now identified epitopes (viral components) shared between SARS-COV-2 and other viruses causing common cold, which are the targets for binding by T-cells,” Dr Kalebi said.
Covid-19 variants
The research has shown that with the emergence of new Covid-19 variants, the study can help in coming up with new vaccines that can tackle future variants.
“Our study complements the small but growing body of evidence that T-cells may protect against SARS-CoV-2 infection and supports the potential utility of second-generation vaccines targeting core proteins,” the study says.
Dr Kalebi told the Nation that T-cells are like master keys that can unlock several locks and, therefore, a great strategy for scientists to use when coming up with vaccines in future.
“Developing vaccines that are geared to driving T-cell immunity and are able to cross react between several viruses might be a better strategy than vaccines that work through antibodies, as antibodies are highly specific, thus limited to the virus targeted,” he explained.
However, the researchers insist that the current vaccines offer protection and people who had previous common colds should not feel safe just yet.
“While this is an important discovery, it is only one form of protection, and I would stress that no one should rely on this alone. Instead, the best way to protect yourself against Covid-19 is to be fully vaccinated, including getting your booster dose,” Dr Rhia Kundu, the study’s lead researcher, said in an article published by the Imperial College London.
Another study published last year by Yale University researchers in the Journal of Experimental Medicine also showed that if people catch a common cold in the earlier days of a Covid-19 infection, their antiviral defences are quite high.
“Triggering these defences early in the course of Covid-19 infection holds promise to prevent or treat the infection,” said Ellen Foxman, lead researcher of the study and assistant professor of laboratory medicine and immunobiology at the Yale School of Medicine in an article published on the Yale University’s website.
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