The Centers for Disease Control and Prevention (CDC) said Monday that the federal public health agency expects more Monkeypox cases in the United States.

Dr. Jennifer McQuiston, an official with the CDC, confirmed that the U.S. has recently registered one case of Monkeypox in Massachusetts along with four Orthopox cases in New York City, Florida, and Utah. The cases of Orthopox, which is part of the family of viruses belonging to Monkeypox, are currently being analyzed at a CDC laboratory in Georgia, according to CNBC.

President Joe Biden weighed in on the Monkeypox, stating that Americans should be “concerned” over the development,

“They haven’t told me the level of exposure yet but it is something that everybody should be concerned about,” the president told reporters.

U.S. President Joe Biden speaks before boarding Air Force One for a trip to Japan at Osan Air Base, Sunday, May 22, 2022, in Pyeongtaek, South Korea. (AP Photo/Evan Vucci)

Jake Sullivan, who serves as Biden’s national security adviser, said the U.S. possesses a supply of “vaccine that is relevant to treating monkeypox.”

White House national security adviser Jake Sullivan speaks during the daily briefing at the White House in Washington, Wednesday, May 18, 2022. (AP Photo/Susan Walsh)

“We have vaccine available to be deployed for that purpose,” the Biden aide added.

On Monday, a former World Health Organization (W.H.O.) official described the Monkeypox cases, which have been confirmed in numerous countries around the world, as “a random event.”

In an interview with the Associated Press, Dr. David Heymann, who formerly headed the W.H.O. emergencies department, said the leading theory to explain the spread of the disease was sexual transmission among gay and bisexual men at two raves held in Spain and Belgium. Monkeypox has not previously triggered widespread outbreaks beyond Africa, where it is endemic in animals.

“We know monkeypox can spread when there is close contact with the lesions of someone who is infected, and it looks like sexual contact has now amplified that transmission,” said Heymann.

The Associated Press contributed to this report.