man dumps feed from a white bucket in front of a lineup of dairy cows behind a metal pole structure
Dairy farmer Brent Pollard gives cows feed at his cattle farm in Rockford, Illinois.
  • The H5N1 bird flu virus has infected a third person in the US, this time with respiratory symptoms.
  • The new patient's cough and sore throat could help the virus get better at infecting humans.
  • Experts fear the US is missing critical opportunities to check the virus's DNA for new mutations.

The H5N1 bird flu virus has once again infected a human. But this time, the unlucky patient had a cough and a sore throat, which is a new milestone for the virus's spread in the US.