A director at the Centers for Disease Control and Prevention on Monday told reporters that the coronavirus is expected to spread in the U.S. despite efforts to contain it, The Daily Beast reports.

Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases, told reporters that federal officials “expect to see more cases of person-to-person spread among close contacts,” and adding later that “the goal here is to slow entry of this virus into the United States.”

So far, the CDC has confirmed 11 cases of coronavirus within the United States, and 167 under investigation have tested negative, with tests for 82 people pending.

“If we take strong measures now, we may be able to blunt the impact of the virus on the United States,” Messonnier said.

“We are preparing as if this were the next pandemic, but we are hopeful still that this is not and will not be the case,” she added, noting that the CDC has implemented a quarantine for the first time in more than 50 years.

“We understand the recent recommendations are concerning,” Messonnier said. “The actions that the federal government is taking are science-based with the aim of protecting the health and safety of all Americans. Please do not let fear or panic guide your actions.”