T cells may help COVID-19 patients — and people never exposed to the virus
People infected with the coronavirus carry immune cells known as T cells that help the body fight off the infection, a study suggests. These cells may help people recover from COVID-19, but their exact role is still unknown. Researchers found T cells that target SARS-CoV-2, the virus that causes COVID-19, in the blood of people who had recovered from a coronavirus infection. Some people who had never been exposed to the virus also had T cells that could recognize the virus, researchers report May 14 in Cell. That finding suggests that previous infections with other coronaviruses, like the ones that cause common colds, could provide some level of protection against the new coronavirus, such as keeping people from developing severe disease. It remains unclear whether these defenses can protect people from a reinfection with SARS-CoV-2, and, if so, for how long. A key part of the immune system, T cells can recognize fragments of viruses. When the cells identify a viral protein, helper T cells release chemical...