(CNN)There's a "reasonable chance" the United States will lose its measles elimination status in October because of ongoing measles outbreaks in New York, according to Dr. Nancy Messonnier, director of the US Centers for Disease Control and Prevention's National Center for Immunization and Respiratory Diseases.

[How vaccines stop diseases like measles]How vaccines stop diseases like measles 01:26
"It certainly is incredibly frustrating and upsetting to the public health community that we may lose measles elimination status, because we do have a safe and effective vaccine," Messonnier said.