One billion people around the world could get vaccinated for Covid-19 with a formula developed at Washington University in St. Louis. It could also be the formula to finally, fatally knock the virus out of our lives. It's a nasal spray and is only one dose. KMOX's Michael Calhoun reports in these stories from 6:05, 7:12, and 8:05 a.m. 9/23/20.