Nearly half of Europeans died from the plague. Now a new study shows a protective gene mutation that survivors passed on to help with future outbreaks might cause other problems.

Studies on white-tailed deer in Pennsylvania and Ontario offer evidence that the mammals are a reservoir for the coronavirus. What are the implications for the course of SARS-CoV-2?

This animated video uses puzzle pieces to show how a coronavirus binds to a cell's surface — and what happens when a mutation occurs.

"Scientifically, it is highly likely that the immune response by this vaccine also can deal with the new virus variant," BioNTech CEO Ugur Sahin said Tuesday.