Two new Omicron subvariants are gaining ground in the U.S. as some people report experiencing respiratory symptoms like ...

Scientists have uncovered a stealthy tactic used by the SARS-CoV-2 virus: one of its proteins can leap from infected cells to ...

A new Covid-19 variant called NB.1.8.1, or Nimbus, represents about a third of new US Covid-19 cases. Dr. Leana Wen answers ...

Most bacterial and viral infections are contagious and spread fast, especially during the rainy season—most people are ...