How scientists detect a new COVID variant
By Douglas Broom
Here's a map showing where low vaccination rates meet high case counts as U.S. Covid infections surge
By Nate Rattner
Covid-19 cases are surging in 46 states. In one hot spot, hospitalized patients are younger than ever, doctor says
By Holly Yan & Madeline Holcombe
The Delta Variant May Cause Different COVID-19 Symptoms
By Carla M. Delgado