LONDON (Reuters) - High levels of so-called “T cells” that respond to the coronavirus could be sufficient to offer protection against infection, an English study said on Tuesday, adding to the evidence of the crucial role they play in immunity to COVID-19. T cells, a type of white blood cell that makes up part of a healthy immune system, are thought to be essential to protect against infection from the SARS-COV-2 coronavirus, and could provide longer term immunity than antibodies. The study on nearly 3,000 people, conducted by Oxford Immunotec and Public Health England (PHE), found that no participants with a high T cell response developed symptomatic SARS-CoV-2 infection when researchers followed up with them.