People who do not have a history of infection with the novel coronavirus infection (COVID-19) are more likely to have had a cold coronavirus as a child, a study has found.
The coronavirus first appeared as a cold virus. Experts estimate that 10-30% of all common colds are caused by the coronavirus.
There are seven types of human-infecting coronaviruses that have been identified so far, of which four (229E, NL63, OC43, HKU1) are coronaviruses that cause relatively mild cold symptoms.
The other three are SARS, MERS, and Corona 19-causing viruses that cause serious symptoms such as severe pneumonia.
Recently, researchers at the La Jolla Institute of Immunology (LJI) in California, USA announced that blood samples from people who have not had a history of COVID-19 infection in the past were re-sampled and analyzed.
The researchers studied blood samples from young adults taken before COVID-19 at the same laboratory, and found that they were all likely to have had multiple exposures to the coronavirus as children.
The blood used in the study was a sample from 32 people, each collected 3 to 7 times over 6 months to 4 years between 2016 and 2019, before the outbreak of COVID-19.
The researchers looked at how immune cells (CD4+ T cells) in their blood responded to the four coronaviruses and the pre-mutated coronavirus, and found that 72 to 81% of the participants had moderate levels of each of the four coronaviruses. showed an immune T-cell response. The extent of the immune response was twice that of the immune response to the COVID-19 virus.
In this study, the researchers exposed participants’ blood to peptides from the cold coronavirus and the coronavirus. As a result, the T-cell and antibody responses were stable and persistent against the four cold coronaviruses.
In addition, people with strong T-cell immune responses to the cold coronavirus showed strong immune responses to COVID-19.
The research team said, “Immunity developed in childhood is maintained into adulthood. That’s why most adults don’t catch a cold from the coronavirus, or pass it on with asymptomatic or mild symptoms.
“This study also bolsters the idea that the immune system responds to the coronavirus in a similar way to the coronavirus and COVID-19,” the researchers said. It is also likely to weaken.”
He added, “It is still too early to be reassured. Like influenza, which still kills many people, the infection of Corona 19 is still a threat.”
Meanwhile, the results of this study were published in the international academic journal ‘Cell Host & Microbe’.
Reporter Lee Bo-bae, Hankyung.com [email protected]