Two pharmaceutical companies, Pfizer and Moderna, have developed coronavirus vaccines that are close to 95 percent effective.
The speedy turnaround in trial results, less than a year after researchers began their work, is record-setting.
We explore the evolution of vaccines as the deadly coronavirus pandemic challenges doctors and scientists racing for a remedy.
Guests:
- Carl Zimmer, author and science writer, The New York Times
- Dr. Howard Markel, physician, professor and medical historian, University of Michigan
