Cattle herds across the US caught bird flu this year Suzanne Kreiter/The Boston Globe via Getty Images
A highly infectious type of bird flu began spreading in dairy cows across the US earlier this year, providing the pathogen with one of its best opportunities to date to evolve and more easily infect people.
Infectious disease experts have been concerned about the virus, called H5N1, for decades. Of the more than 900 people worldwide who are known to have caught it since 2003, around half died as a result.
Article amended on 11 December 2024
This article has been changed to correct the recovery statuses of the people with known infections.
