Highly pathogenic avian influenza A(H5N1) viruses have caused widespread infections in dairy cows and poultry in the United ...

Most human cases of bird flu in North America have been mild, a fact that’s underscored by a new study of the first 46 ...

So far, the H5N1 virus isn't transmitted between people — but the CDC has found a mutation in a human case "concerning." ...

Genetic analysis of H5N1 bird flu virus that infected a Canadian teenager shows 'worrisome' mutations, new studies reveal.

A virologist explains that why this probably isn’t the big one — but that it’s a sign of bad things happening with the virus.

Amid a "concerning" new mutation in bird flu that may indicate the virus could begin to more easily infect humans, what are ...

A genetic analysis suggests the bird flu virus mutated inside a Louisiana patient who contracted the nation’s first severe ...

The virus in the first severe human bird flu case in the U.S. was found to have mutated. Newsweek's live blog is closed.

The virus has spread among dairy cattle, humans and other mammals. But officials say the current public health risk is low.

Tiny genetic alterations could help the bird flu virus enter cells in the upper respiratory tract, the C.D.C. said. But there ...

A genetic analysis of viral samples from a patient in Louisiana hospitalized with the first severe case of bird flu showed ...