As much as half of the world's population may have some immunty to coronavirus, a small but growing body of research suggests. Tests done on donated blood in the US found that about 50 percent of the samples had immune T cells that reacted to coronavirus, suggesting that the donors' bodies might have the natural ability to fight of the deadly virus. Some people may have immune T cells to other coronaviruses that could fight SARS-CoV-2, recent research suggestsIn March, a member of a Skagit County, Washington choir went to their usual practice, feeling a bit ill, but unaware that they had coronavirus. Most research on coronavirus immunity has focused on antibodies, immune cells that develop after the body has been exposed to a new pathogen. Scientists think that some people may have developed T cells for other coronaviruses that are 'cross-reactive' with SARS-CoV-2 because they are sufficiently similar.

Source: Daily Mail September 19, 2020 00:55 UTC