H5 influenza virus, also known as H5 bird flu, is causing outbreaks in wild birds, poultry, and U.S. dairy cows. Human infection is rare; from March to July 29, 2024, 13 people in 3 states were infected. All U.S. human cases have been linked to direct contact with infected cows or poultry. Federal funds have been awarded to Moderna to develop an mRNA-based vaccine against H5 bird flu.

People should avoid direct contact with wild birds and other animals. Current cases are from direct contact with infected animals, not spread person to person.

According to CDC, the current public health risk is low, and continues to be monitored. CDC and state and local health departments monitor people exposed to infected birds, poultry, cattle or other animals for 10 days after exposure. Individuals are tested for novel influenza A.

Since February 25, 2024, more than 36,000 specimens have been tested at public health labs for avian influenza A(H5) or other novel influenza viruses.

CDC continues to support and protect farm workers. This includes specific outreach to farm workers in affected counties through Meta (Facebook and Instagram), electronic signs, and audio (Pandora). Since May 30, when these materials became available, Meta outreach was displayed more than 12 million times.

Moderna was awarded $176 million in federal funds through the Rapid Response Partnership Vehicle (RRPV) for H5 bird flu vaccine development.

At this time, bird flu does not easily spread between humans. Scientists are monitoring existing cases for possible mutations that could change this.