Fox News medical contributor Dr. Marc Siegel answers parents’ questions on whether it’s safe to return to in-person learning amid the coronavirus pandemic. The Food and Drug Administration has issued an emergency use authorization for a new coronavirus testing method using the body’s T-cells — which could help better diagnose COVID long-haulers. The T-Detect COVID-19 test — developed by Seattle-based Adaptive Biotechnologies Corp. in collaboration with Microsoft — is billed as a "next generation" screening method that analyzes DNA from T-cells in blood samples instead of current testing methods that screen for immune proteins. "The T-Detect COVID test will be a useful tool to help determine if a person previously had COVID-19," the FDA announced Friday. "This is especially important for people who may have exhibited symptoms previously or believe they have been exposed but have not tested positive."