Some 16 states had "very high" levels of the virus present in wastewater during the week of Christmas, an increase from the week before.

The world first became aware of Covid-19 five years ago. We evaluate where we are, remember how we got here, and consider ...

COVID symptoms can be mild, severe, or nonexistent, according to the CDC—and can appear as late as two weeks after you’ve ...

Despite studying the SARS-CoV-2 virus for five years, scientists still have questions, from the extent to which it can ...