Gaithersburg-based Emergent BioSolutions was granted federal approval to use its smallpox vaccine in people at high risk for mpox infections that have been surging in Africa.

Emergent had been making the vaccine called ACAM2000 for the U.S. Strategic National Stockpile in case of a bioterrorism attack.

It’s been federally approved for smallpox since 2007 but wasn’t used much previously against mpox, another orthopoxvirus, because it can’t be used with people with compromised immune systems. That includes people with HIV.

The U.S. Food and Drug Administration relied on previous human studies to expand uses to mpox, previously known as monkeypox, in hopes of expanding access to protections.

“This expanded indication for ACAM2000 comes at a critical time as the global health community comes together to ensure an effective and cohesive response to the recent upsurge in mpox cases,” said Joe Papa, Emergent’s president and CEO, in a statement.

“We believe Emergent is poised to support the global response needed by actively engaging with world health leaders, as well as deploying product currently available in inventory based on the needs, as well as the ability to increase supply.”

Cases of mpox had begun spreading to non-endemic countries, including the United States, in 2022. The reemergence has been centered in African countries, and the World Health Organizations declared a Public Health Emergency of International Concern last month.

There have been 787 cases in Maryland since mpox first surfaced in the state, with about a third of the cases in Baltimore. The city continues to offer the non-Emergent vaccine through its health clinics on a walk-in and appointment bases. Almost 11,500 people have been vaccinated in the state so far.

Emergent did not say where the mpox vaccine would be produced. But it will not be making it in Baltimore, where it long had a major manufacturing presence. The plant at Bayview in East Baltimore has been shuttered after a troubled period where it produced COVID-19 vaccine that was possibly contaminated.

About 525 millions of doses of bulk vaccine had to be discarded. The problems with the lines and poor record keeping led the Biden administration to cancel the federal contract for vaccines, which had been signed during the Trump administration.

The troubles led to lawsuits, layoffs and a congressional inquiry. The company said at the time that making massive amounts of both AstraZeneca and Johnson & Johnson vaccines at the same time turned out to be too complex and unrealistic.

The company has since effectively left Baltimore. It announced in June it would sell its plant in the Carroll Camden industrial area to an affiliate of Bora Pharmaceuticals Co. in a $30 million deal. That plant was a so-called fill center, where vaccine and other therapeutics were packaged for market. The deal closed Aug. 20.