It may seem like everyone is either getting COVID-19 this summer, or knows someone who has. That’s because for the fourth year in a row, COVID cases are experiencing a summer surge.The CDC now tracks COVID-19 mostly through wastewater and found that viral activity has multiplied more than four times from the beginning of May to now. The CDC classifies the viral activity level as “high.”So what’s behind this surge? And why does it keep happening in the summer?SciFri’s John Dankosky talks with Jessica Malaty Rivera, infectious disease epidemiologist and science communicator at the de Beaumont Foundation, about what’s behind the surge and how to stay safe.Transcripts for each segment will be available 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.