The Centers for Disease Control and Prevention (CDC) last year took steps to guard against the spread of smallpox and monkeypox, which recently was found in the U.S. and internationally.
A case of monkeypox was confirmed in an American who recently traveled to Nigeria. A handful of cases of monkeypox also have been reported or are suspected in Britain, Portugal, and Spain.
A CDC epidemiologist told Fortune that the confirmed U.S. case constituted a "public health urgency," but not an emergency.
"A lot of people are working hard around the clock, supporting state health departments — not just in this case, but in preparation for other cases that may occur," said Andrea McCollum, an epidemiologist with the CDC's Poxvirus and Rabies Branch.
Scientists in Africa, who typically deal with monkeypox there, are quite baffled about the outbreaks in the United States and Europe.
Cases of the smallpox-related disease have previously been seen only among people with links to central and West Africa. But in the past week, Britain, Spain, Portugal, Italy, U.S., Sweden and Canada all reported infections, mostly in young men who hadn’t previously traveled to Africa, the Associated Press reports.
There are about 80 confirmed cases worldwide and 50 more suspected ones, the World Health Organization said. France, Germany, Belgium and Australia reported their first cases Friday.
“I’m stunned by this. Every day I wake up and there are more countries infected,” said Oyewale Tomori, a virologist who formerly headed the Nigerian Academy of Science and who sits on several WHO advisory boards.
“This is not the kind of spread we’ve seen in West Africa, so there may be something new happening in the West,” he told the AP.
President Joe Biden on Monday sought to calm concerns by saying he did not see the need to institute strict quarantine measures after recent cases of monkeypox were identified.
The CDC and the Maryland Department of Health in November confirmed a case of monkeypox in a resident who had returned from Nigeria to the U.S. The CDC and the Texas Department of State Health Services confirmed a similar case in July.
CDC vaccine advisory committee meetings late last year indicated the U.S. also was focused on the threat of smallpox. The public health agency has been collaborating with vaccine manufacturers to make new, safer vaccines and determine how well they work.
ACAM2000 and JYNNEOS (also known as Imvamune or Imvanex) are the only two licensed smallpox vaccines in the U.S., the CDC said.
Newsweek last week reported the U.S. government ordered millions of doses, worth $119 million, for JYNNEOS vaccines, produced by biotechnology company Bavarian Nordic.
In November, the CDC said several vials labeled "smallpox" were found at a vaccine research facility in Pennsylvania.
"There is no indication that anyone has been exposed to the small number of frozen vials," the CDC told CNN in a statement.
Monkeypox is a rare disease related to smallpox and cowpox, first identified in 1958 among colonies of monkeys kept for research, according to the CDC. Normally it's found in Africa.
The virus causes fever, muscle aches, and lesions that progress through various stages before scabbing. It's thought to be fatal in about 10% of cases.
"Monkeypox is thankfully less severe than smallpox ever was, with a lower mortality rate," Dr. Alexandra Brugler Yonts, an infectious disease specialist at Children's National in Washington, D.C., told Fortune.
Last year, biosecurity and public health experts war-gamed what might happen in the event that terrorists released a genetically engineered, smallpox vaccine-proof monkeypox strain, Britain's Express website reported.
This exercise was a collaboration between the WHO, the US National Security Council, both the African and Chinese centres for disease control and prevention and representatives from various biotechnology and pharmacy firms, according to the Express.
The war gamers imagined an altered pox playing out for 18 months, during which more than three billion people were infected with the disease and more than 250 million died as a result.
While the fictional pandemic was just that, experts said that the exercise helped them to reach a number of useful, if grim, predictions about how the next pandemic might play out, according to the Express.
The Associated Press contributed to this story.