T cells can seek and destroy SARS-CoV-2 (yellow) infected cells. By Mitch LeslieScience's COVID-19 reporting is supported by the Pulitzer Center.Immune warriors known as T cells help us fight some viruses, but their importance for battling SARS-CoV-2, the virus that causes COVID-19, has been unclear.
Now, two new studies reveal that infected people harbor T cells that target the virus—and may help them recover. Both studies also found that some people never infected with SARS-CoV-2 have these cellular defenses, most likely because they were previously infected with other coronaviruses.“This is encouraging data,” says virologist Angela Rasmussen of Columbia University.