Infectious disease doctor Abraar Karan says it's the question he's asked most often about SARS-CoV-2. So how does that happen? Here's his answer.

The official emergency is over but COVID is still here. And that means ... lots of questions. We asked our readers what's on their mind and then called on experts for advice.

A leaked CDC document compared it to the highly contagious children's disease. Data does not support this claim. Nonetheless, the variant is one of the world's most contagious respiratory diseases.

A letter from over 200 scientists to the World Health Organization asks for further investigation into how the virus spreads. WHO responded at a press conference on Tuesday.