A 13-year-old girl in Canada became so sick with H5N1, or bird flu, in late 2024 that she had to be put on a ventilator. Around the same time, a senior in Louisiana was diagnosed with the first “severe” case in the U.S.
As bird flu continues to ramp up, many are wondering what tools—namely, vaccines—we have to fight it if such intervention becomes necessary.
“Public-health and infectious disease folks around the world are watching bird flu very, very carefully,” says Dr. William Schaffner, professor of infectious diseases at Vanderbilt University Medical Center and spokesperson for the Infectious Disease Society of America. “The concern is that this virus could acquire the capacity to attach to human cells and spread widely. That would be opening the door to a new pandemic for sure.”
For that to happen, the H5N1 virus would have to develop the right mutations that allow it to more easily infect human cells—a process that could occur more easily if someone were to be infected with both seasonal flu and H5N1, for instance, allowing the two viruses to exchange genetic information and recombine into a strain that readily infects and spreads among people.