The COVID-19 vaccine holds promise for bringing an end to the pandemic. But some have questioned the rapid development of the vaccine — so I talked with some scientists about how pharmaceutical companies were able to work so quickly. Michael Olson is an assistant professor of immunology with SIU School of Medicine. He saidthe first thing to understand how the body develops an immune response. “So your body is trained to recognize things that are not self, so something that's foreign,” Olson said