As the virus continues to mutate, the C.D.C. urged Americans to roll up their sleeves again for annual Read More

Among Americans aged 60 to 74, only those with certain health conditions need to receive the shots, the agency concluded.Read More

There is no guarantee that a person-to-person virus would be benign, scientists say, and vaccines and treatments at hand may Read More

Huge die-offs of elephant seals occurred after the virus gained nearly 20 troublesome new mutations, scientists found.Read More

The worker had respiratory symptoms, unlike the first two. But the risk to the public remains low, federal health officials Read More