In the latest episode of "The Health Variant" podcast, host and NewsMD Health Correspondent Jeremy Fugleberg talks with immunologist Dr. Marc K. Jenkins at the University of Minnesota. Jenkins discusses what we know and don't know about the omicron variant, explains about why it's not so easy to know if you have the natural immunity you need to fight off COVID-19 (but could in the foreseeable future), and details what happened to the hopes for herd immunity.