Does a faint line on COVID or flu test count as a negative? What it means

COVID and flu tests aren't designed to tell you how sick you are, but if you use them to monitor your infection, they can ...

Do I still have to quarantine if I catch COVID? See latest California guidelines

Several illnesses - including COVID-19 - are currently circulating statewide.

How long you’re contagious with the flu — and when it’s safe to go out

How long are you contagious with the flu? Experts say you can spread the virus for five to seven days after symptoms start, ...

NASA fueling test sets stage for Artemis II moonshot mission

If the fueling test goes well, the Artemis II flight around the moon and back could take off as early as Feb. 8.

'Chance for rocket to talk to us' NASA says of Artemis II launch delay

After pre-launch testing revealed rocket issues, NASA has delayed the Artemis II launch until March. Here's the latest.

4-in-1 at-home test for flu, COVID-19 and RSV now available

CLEVELAND, Ohio — Families can now test for flu, COVID-19 and respiratory syncytial virus with one at-home test. The ...

Scientists Find New Immune Clue Behind Long COVID’s Lingering Symptoms

A detailed analysis of immune cells in Long COVID patients has revealed a previously unknown molecular signature linked to lingering symptoms. In Germany, Long COVID develops in up to about one in ten ...