The number of people experiencing “long COVID” is unknown, but experts estimate that millions of Americans could be affected. Could an out-of-order immune system be to blame for lingering symptoms? PRODUCTION CREDITS: Produced by: Emily Zendt Production Assistance: Christina Monnen…

Thomas Lewis, author of “The End of Alzheimer’s: A Differential Diagnosis Toward a Cure,” is a microbiologist with a Ph.D. from MIT. He’s done a lot of work on diagnostic testing, and in this interview, we explore how retinal assessment…