Scientists have discovered differences in the immune response that could explain why some people seem to reliably escape Covid infection.
The study, in which healthy adults were intentionally given a small nasal dose of Covid virus, suggested that specialised immune cells in the nose could see off the virus at the earliest stage before full infection takes hold. Those who did not succumb to infection also had high levels of activity in a gene that is thought to help flag the presence of viruses to the immune system.
