A scanning electron micrograph of a human T lymphocyte (also called a T cell) from the immune system of a healthy donor, in this National Institute of Allergy and Infectious Disease (NIAID) handout photo obtained March 30, 2021. (Photo by Handout / National Institute of Allergy and Infectious Diseases / AFP)  In good news about … Continue reading ‘Killer T cells’ dodge variants to help prevent severe COVID-19