The ongoing monkeypox outbreak has officially been declared a global health emergency of international concern as cases continue to rise domestically and internationally.

The declaration comes on the heels of the World Health Organization (WHO) committee convening on July 21 to discuss measures to curb the spread of the rare disease. According to Reuters, there were 3,000 reported global monkeypox cases at the end of June. That number has since ballooned to more than 16,000. On Friday (July 22), the U.S. reported its first two monkeypox cases in children. The patients are a toddler who lives in California and an infant who is not a U.S. citizen. The disease causes flu-like symptoms and a rash that can last for weeks. There have been five confirmed monkeypox related deaths in Africa.

WHO head Tedros Adhanom Ghebreyesus said that while anyone can contract the disease from skin-to-skin contact, the rise in cases continues to be predominantly seen in same-sex interactions among men. “Although I am declaring a public health emergency of international concern, for the moment this is an outbreak that is concentrated among men who have sex with men, especially those with multiple sexual partners,” said Ghebrevesus on Saturday (July 23).

He further reiterated that, “For the moment, this is an outbreak that’s concentrated among men who have sex with men, especially those who have multiple partners. That means that this is an outbreak that can be stopped with the right strategies in the right groups.”

Since May, health officials have also seen significant spread of the virus at “cluster events” where large groups of people have been gathered. In response to the growing number of cases in the U.S., the government has provided shipments of 300,000 vaccines across the country and its territories. Currently, the only two Food & Drug Administration approved vaccines available are JYNNEOS and ACAM2000.