The women, ages 72 and 56, were both from Guangdong province in southern China.
The infected woman, who is hospitalized, was likely exposed to H5N1 through contact with her infected backyard poultry flock.
In other developments, Zoetis announced it has received USDA's conditional approval for its updated poultry vaccine.
As the virus struck more layer and other commercial poultry farms, state wildlife officials continue to warn about wild bird detections.
The findings suggest that cases in people and animals in other states have yet to be identified, the authors say.
The US has recorded 68 human cases of avian flu since 2024.
USDA testing confirmed detections in cats from California, Montana, and Oregon.
Both patients, boys ages 2 and 15 years old, are from Hunan province in southern China.
Among several more outbreaks on commercial farms, one was at a layer facility in Pennsylvania that has nearly 2 million birds.
Detection of the D1.1. genotype, linked to 2 severe infections in people, came from the national milk testing program.
