The BCG vaccine is given to millions of kids every year. Can it help fight COVID? Dr. Moshe Arditi at Cedars/Sinai has been leading a fascinating clinical trial to determine whether this vaccine might help teach the immune system to fight off not just tuberculosis but the pandemic we now face. And — possibly — to be better at fighting viruses in general. We spoke with Dr. Arditi about the trial and what its results so far might mean.