H5N1 Information

What is H5N1 and why did we make a dedicated page about it?

H5N1 is an influenza virus (also known as the flu) that has caused severe outbreaks in poultry and occasionally in humans. Human infections are rare and typically result from direct contact with infected animals. Nearly 1000 human infections have been confirmed to date, including almost 500 deaths. 
 

H5N1 is considered to have high pandemic potential due to its prevalence in animals, ability to infect and severely sicken humans, and the natural ability of flu viruses to rapidly mutate and adapt to new hosts.

The recent emergence of a new H5N1 strain, Clade 2.3.4.4b, has accelerated H5N1's spread to new animal species, including mammals. Since 2024, the virus has spread rapidly in U.S. cattle for the first time, highlighting its expanding host range and increasing the risk in the United States.