CNN: “A recently published summary article in the journal Nature Reviews Immunology put forth a tantalizing possibility: A large percentage of the population appears to have immune cells that are able to recognize parts of the SARS-CoV-2 virus, and that may possibly be giving them a head start in fighting off an infection. In other words, some people may have some unknown degree of protection. ‘What we found is that people that had never been exposed to SARS Cov2 … about half of the people had some T-cell reactivity,’ co-author of the paper Alessandro Sette from the Center for Infectious Disease and Vaccine Research at La Jolla Institute for Immunology, told CNN.”