In the race to study immunity to the virus, scientists first focused on antibodies -- proteins that stick to and disable foreign invaders. That’s because creating antibodies is the basis for most successful vaccines, so scientists are interested in learning who develops coronavirus antibodies, how long they stick around, and how effective they are at keeping people from getting infected again. But recent studies show there may be another weapon inside the human body that can rouse fresh antibody soldiers long after the first have left the battlefield. Bloomberg senior editor Jason Gale explains that T cells may be part of the key to blunting the coronavirus contagion.