Just The News:
A new study from scientists in the United States suggests that a significant majority of the population may already have some level of immunity to the coronavirus, a possible explanation for why so many individuals seem to experience few to no symptoms from the disease.
The study, written by researchers in California, New York and North Carolina and soon to be published in the journal Cell, discovered that certain types of cells in blood samples taken from donors in 2015-2018—well before COVID-19 arose—were reactive against the COVID-19 virus. In other words, those blood samples were at least partially immune from the coronavirus even though they had never been exposed to it.
“CD4+ T cell responses were detected in 40-60% of unexposed individuals. This may be reflective of some degree of crossreactive, preexisting immunity to SARS- CoV-2 in some, but not all, individuals,” the researchers state in the paper.