The US Centers for Disease Control and Prevention ended its emergency response for bird flu as the outbreak that sickened dozens of people, spread to cattle and drove up egg prices has abated.

Doctors and researchers said the moves will make it harder to detect potentially dangerous changes. If the virus continues to jump between species or the human case count grows, there’s a greater risk that it could mutate and become more easily transmissible between people,

The U.S. Centers for Disease Control and Prevention said on Monday it has ended its emergency response for H5N1 bird flu, owing to a decline in animal infections and no reports of human cases since February.