A contagious new COVID-19 variant called NB.1.8.1, aka "Nimbus," is now dominant in the United States, CDC data show. What to know about symptoms and vaccines.

In patients with COVID-19, preexisting immunity and Omicron infection were associated with reduced disease severity and upper respiratory symptom presentation.

The Stratus variant of Covid, formerly known as XFG, is concerning health officials due to its ability to reinfect people ...

A new strain of COVID-19, XFG, is spreading rapidly across the world, including in the United States. Anecdotally, people who ...

While you are soaking up the summer sun, doctors say you can still get sick, including from two new COVID strains that are ...

While you are soaking up the summer sun, doctors say you can still get sick, including from two new COVID strains that are ...

The WHO warns that a new, more dominant COVID strain is on the loose—and spreading rapidly. What to know about the XFG ...

In the UK and the USA, risk of reporting a positive test for COVID-19 was increased among front-line health-care workers. Health-care systems should ensure adequate availability of PPE and develop ...