Much is still a mystery to health experts in the path to fight against COVID-19

California has impressively low Covid-19 numbers, at the moment. What leads to these ebbs and surges of cases?  To answer your questions, KCBS Radio news anchors Dan Mitchinson and Holly Quan spoke with Andrew Noymer, epidemiologist, demographer [and associate professor of population health and disease prevention] at UC Irvine.