The fate of a Canadian teenager who was infected with H5N1 bird flu in early November, and subsequently admitted to an intensive care unit, has finally been revealed: She has fully recovered.But genetic analysis of the virus that infected her body showed ominous mutations that researchers suggest potentially allowed it to target human cells more easily and cause severe disease — a development the study authors called "worrisome.

In 2024, at least 66 human cases of bird flu have been reported in the United States, each one raising the risk of another pandemic like COVID-19. So far, most cases have been described as “mild,” which means they weren't hospitalized.

When, where and how the H5N1 bird flu virus may evolve and its capacity to spark a pandemic is hard to predict — in part, some researchers say, because of federal restrictions on gain-of-function research.

A Canadian teenager has fully recovered from H5N1 bird flu, but genetic analysis revealed concerning mutations in the virus.

The CDC previously confirmed the first severe human case of bird flu in Louisiana, but now the CDC has confirmed a virus mutation. Find out more here

Los Angeles County health officials have identified three more cats with presumptive H5N1; the source of the virus has not yet determined, but experts suspect raw meat.