Immunity to coronavirus may be far more widespread than thought

Two weeks ago I wrote here about a study by the La Jolla Institute for Immunology in California, which found that between 40 and 60 per cent of people who had never been exposed to SARS-CoV-2 – the virus which causes Covid 19 – nevertheless seemed to develop an immune response to the disease in their T Cells. They appeared to have a cross-reactive immunity which had been gained through exposure to other...