Four years ago this week, the world as we know it changed. Schools shut down, offices shuttered, and we hunkered down at home with our Purell and canned foods, trying to stay safe from a novel, deadly coronavirus. Back then most of us couldn’t fathom just how long the pandemic would stretch on.And now four years later, some 1.2 million people have died in the U.S alone and nearly 7 million have been hospitalized as a result of a COVID-19 infection, according to the CDC.So, what have we learned about how COVID-19 attacks the body? What can be done for long COVID sufferers? And what can we expect in the future?Ira analyzes this era of the pandemic with Hannah Davis, co-founder of the Patient-Led Research Collaborative in New York City, and Dr. Akiko Iwasaki, immunobiologist at Yale Medical School in New Haven, Connecticut.Transcripts for each segment will be available the week after the show airs on sciencefriday.com Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.