The small-scale study, which was published in Nature Communications, enlisted the help of 52 people who resided with someone who had just contracted Covid-19.
After a cold, those who formed a “memory bank” of certain immune cells to help avoid subsequent assaults looked to be less likely to develop Covid.
Experts believe that no one should rely only on this defense, and that immunizations will continue to be important.
They believe, however, that their findings may give significant insight into how the body’s immune system combats the infection.
Because Covid-19 is caused by a coronavirus, and certain colds are caused by other coronaviruses, scientists wondered if immunity to one may assist with the other.
However, researchers warn that thinking that everybody who has recently had a cold is automatically protected against Covid-19 is a “grave mistake” as not all colds are caused by coronaviruses.
The Imperial College London researchers sought to know why some people get Covid after being exposed to it and others don’t.
They concentrated their research on T-cells, which are an important aspect of the immune system. Some of these T-cells are capable of killing any cells infected with a specific danger, such as a cold virus. After the cold has passed, some T-cells stay in the body as a memory bank, ready to develop a defense when the virus reappears.
Researchers evaluated 52 persons who had not yet been vaccinated but lived with people who had just tested positive for Covid-19 in September 2020. During the 28-day research period, half of the group received Covid and the other half did not.
A third of those who were not infected with Covid had significant amounts of particular memory T-cells in their blood. These were most likely formed when the body was infected with another closely similar human coronavirus, most often a common cold, according to the researchers.
Other factors, like as ventilation and how contagious their household contact was, might also influence whether someone contracted the illness, according to the researchers.
Although this was a tiny research, Dr Simon Clarke of the University of Reading said it adds to our understanding of how our immune system fights the virus and might help with future vaccinations.
He said, ” “It’s important not to over-interpret these numbers. It’s doubtful that someone who has died or has had a more serious infection has never experienced a coronavirus-caused cold.” It’s also a fallacy to believe that everybody who has recently had a cold is immune to Covid-19, as coronaviruses only responsible for 10-15 percent of all colds “colds,” says the author. Professor Ajit Lalvani, the study’s principal author, concurred that immunizations were essential for protection. He said, ” “Learning from what the body does well might aid in the development of new vaccines.
Current vaccines target spike proteins on the virus’s outer surface, but these spike proteins can alter when new varieties emerge.
T-cells in the body, on the other hand, target internal viral proteins, which do not vary as much from one version to the next, implying that vaccinations that better harness the action of T-cells might give broader, longer-lasting protection against Covid, he added.